Diabetes mellitus is a chronic metabolic disease characterized by elevated blood glucose caused by inadequate insulin production, impaired insulin action, or both. Without appropriate treatment, diabetes can damage the heart, kidneys, eyes, nerves and blood vessels, leading to complications such as cardiovascular disease, chronic kidney disease, blindness, neuropathy and diabetic foot disease.

The treatment of diabetes has changed substantially in recent years. Modern diabetes management is no longer focused only on lowering blood glucose. Treatment should also reduce cardiovascular and kidney complications, manage body weight, prevent hypoglycemia, improve quality of life and address other metabolic conditions.

The American Diabetes Association (ADA) Standards of Care 2026 emphasizes individualized, person-centered treatment and selection of medications according to cardiovascular disease, heart failure, chronic kidney disease, obesity, hypoglycemia risk, cost, access, tolerability and patient preferences.

Important: Diabetes treatment should be individualized by a qualified healthcare professional. Medication selection and dosing depend on the type of diabetes, kidney and liver function, age, pregnancy status, comorbidities, glucose levels and risk of hypoglycemia.

1. Goals of Diabetes Treatment

The major goals of diabetes treatment are to:

Achieve individualized blood glucose targets
Prevent or delay diabetes complications
Reduce cardiovascular risk
Protect kidney function
Achieve and maintain a healthy body weight
Avoid hypoglycemia
Treat hypertension and dyslipidemia
Promote physical activity and healthy nutrition
Improve quality of life
Provide diabetes self-management education and support

Importantly, glycemic control is only one component of comprehensive diabetes care. Cardiovascular risk factors, kidney disease, obesity, eye disease, neuropathy and foot health should also be assessed regularly.

2. Individualized Blood Glucose Targets

For many nonpregnant adults with diabetes, the ADA 2026 recommends an HbA1c target below 7%, provided this can be achieved safely without significant hypoglycemia or excessive treatment burden.

Typical glucose targets for many adults are:

Measurement	Common target
HbA1c	<7%
Pre-meal glucose	80–130 mg/dL (4.4–7.2 mmol/L)
Peak post-meal glucose	<180 mg/dL (<10.0 mmol/L)
CGM time in range	>70%

Targets should be individualized.

A lower HbA1c target, such as <6.5%, may be appropriate for selected healthy individuals when treatment carries a low risk of hypoglycemia. Conversely, less stringent targets may be appropriate for people with frailty, major comorbidities, cognitive impairment or substantial hypoglycemia risk.

3. Lifestyle Management

Lifestyle intervention remains a fundamental component of diabetes treatment.

Healthy eating

There is no single diet that is appropriate for every person with diabetes. Nutrition should be individualized according to:

Body weight
Cultural food preferences
Economic circumstances
Cardiovascular risk
Kidney function
Glycemic targets
Medication regimen

Important principles include:

Emphasize vegetables and high-fiber foods
Choose minimally processed foods
Prefer whole grains and high-quality carbohydrates
Include appropriate sources of protein
Reduce sugar-sweetened beverages
Limit refined carbohydrates
Reduce excessive saturated fat
Avoid excessive calorie intake
Choose water or unsweetened beverages instead of sugary drinks

For people who are overweight or obese, even modest weight loss can improve glycemic control and cardiometabolic risk.

4. Physical Activity

Regular physical activity improves:

Insulin sensitivity
Blood glucose control
Cardiovascular fitness
Blood pressure
Body composition
Quality of life

A practical approach is to combine:

Aerobic activity
Resistance training
Reduction of prolonged sitting
Increased daily movement

Exercise prescriptions should be individualized, particularly in people with cardiovascular disease, advanced kidney disease, neuropathy, retinopathy or other complications.

5. Diabetes Self-Management Education and Support

Patients should be taught how to manage diabetes in everyday life.

Education should include:

Medication use
Glucose monitoring
Recognition and treatment of hypoglycemia
Nutrition
Exercise
Sick-day management
Foot care
Medication adherence
When to seek medical attention

The ADA 2026 considers diabetes self-management education and support and healthy behaviors essential components of diabetes treatment.

6. Treatment of Type 1 Diabetes

People with type 1 diabetes require insulin therapy because pancreatic insulin production is severely deficient or absent.

The 2026 ADA/EASD consensus emphasizes insulin replacement together with diabetes technology, glucose monitoring, education and management of cardiovascular and other risk factors.

Insulin therapy

Insulin can be delivered by:

Multiple daily injections
Insulin pumps
Automated insulin delivery systems

Modern treatment increasingly incorporates continuous glucose monitoring (CGM) and automated insulin delivery.

The ADA 2026 identifies automated insulin delivery systems as the preferred insulin-delivery method over multiple daily injections or conventional pump approaches for many people with type 1 diabetes, depending on individual circumstances and preferences.

7. Treatment of Type 2 Diabetes

Type 2 diabetes treatment generally combines lifestyle management with glucose-lowering medication.

Pharmacologic treatment should generally begin when type 2 diabetes is diagnosed rather than delaying medication unnecessarily. The choice of medication should be individualized according to glycemic needs, cardiovascular disease, heart failure, kidney disease, obesity, hypoglycemia risk, adverse effects, cost and patient preferences.

8. Metformin

Metformin remains an important treatment option for type 2 diabetes.

Advantages include:

Effective glucose lowering
Low risk of hypoglycemia when used alone
Low cost
Long clinical experience
Generally weight neutral or associated with modest weight loss

It is particularly useful when there are no specific cardiovascular, kidney or obesity-related considerations that favor another medication.

However, kidney function must be considered before and during treatment.

9. GLP-1 Receptor Agonists

GLP-1 receptor agonists include medications such as:

Semaglutide
Dulaglutide
Liraglutide

They can provide substantial glucose lowering and are particularly useful in people with:

Obesity or overweight
High cardiovascular risk
Established cardiovascular disease
Certain kidney disease
MASLD/MASH in appropriate patients

GLP-1–based therapies generally have a low intrinsic risk of hypoglycemia unless combined with insulin or insulin secretagogues.

Common adverse effects include gastrointestinal symptoms such as:

Nausea
Vomiting
Diarrhea
Constipation
Reduced appetite

10. Dual GIP/GLP-1 Receptor Agonist

Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist.

It can produce substantial reductions in:

HbA1c
Body weight

The ADA 2026 recommends prioritizing glucose-lowering therapies with beneficial effects on body weight in people with diabetes and overweight or obesity. GLP-1 receptor agonists or dual GIP/GLP-1 receptor agonists with greater weight-loss efficacy, such as semaglutide or tirzepatide, are highlighted for appropriate patients.

11. SGLT2 Inhibitors

SGLT2 inhibitors include:

Empagliflozin
Dapagliflozin
Canagliflozin
Ertugliflozin

These medications lower blood glucose by increasing urinary glucose excretion.

Their importance extends beyond glucose lowering.

They can provide important benefits in selected people with:

Heart failure
Chronic kidney disease
Cardiovascular disease
Increased cardiovascular or renal risk

For people with type 2 diabetes and heart failure, an SGLT2 inhibitor is recommended for cardiovascular and heart-failure benefits irrespective of HbA1c.

For people with type 2 diabetes and CKD, ADA 2026 recommends an SGLT2 inhibitor with demonstrated benefit when eGFR is ≥20 mL/min/1.73 m², with continuation possible as kidney function declines, depending on the clinical situation.

Potential adverse effects include:

Genital mycotic infections
Volume depletion
Increased urination
Rare diabetic ketoacidosis, including euglycemic DKA

Patients should receive appropriate sick-day and perioperative instructions.

12. Sulfonylureas

Sulfonylureas can effectively reduce blood glucose and are relatively inexpensive.

However, they can cause:

Hypoglycemia
Weight gain

Because newer therapies may offer additional cardiovascular, kidney or weight benefits, sulfonylureas are often not the preferred option when those considerations are important.

13. DPP-4 Inhibitors

DPP-4 inhibitors include:

Sitagliptin
Linagliptin
Saxagliptin
Alogliptin

They generally have:

Modest glucose-lowering efficacy
Low hypoglycemia risk when used alone
Weight-neutral effects

They may be useful when treatment simplicity and tolerability are priorities.

GLP-1 receptor agonists should generally not be combined with DPP-4 inhibitors because they act through overlapping incretin pathways without providing meaningful additional benefit.

14. Thiazolidinediones

Pioglitazone improves insulin sensitivity.

It may be useful in selected patients but can cause:

Weight gain
Edema
Fluid retention
Increased risk of heart failure in susceptible individuals
Increased fracture risk

Therefore, careful patient selection is required.

15. When Should Combination Therapy Be Used?

Combination therapy may be appropriate when:

HbA1c is substantially above target
Monotherapy is unlikely to achieve the desired goal
Rapid improvement is needed
Cardiovascular or kidney protection is an important treatment objective

The ADA 2026 recommends considering combination therapy as initial treatment in appropriate adults with type 2 diabetes to shorten the time needed to reach individualized glycemic goals.

16. When Is Insulin Needed in Type 2 Diabetes?

Insulin should be considered when there is:

Severe hyperglycemia
Catabolic symptoms
Significant weight loss
Ketosis or ketoacidosis
Very high HbA1c or glucose levels
Symptomatic hyperglycemia
Failure of appropriate non-insulin therapy
Situations in which insulin is temporarily or permanently required

Insulin may be used alone or together with other glucose-lowering medications.

When insulin is started, clinicians should monitor for hypoglycemia and avoid excessive basal insulin dosing.

17. Diabetes and Chronic Kidney Disease

Kidney protection is now a major component of diabetes treatment.

Patients with diabetes should be assessed for:

eGFR
Urine albumin-to-creatinine ratio
Blood pressure
Cardiovascular risk

For type 2 diabetes with CKD, treatment may include:

SGLT2 inhibitor when appropriate
GLP-1 receptor agonist with demonstrated benefit
Renin-angiotensin system blockade when indicated
Statin therapy
Blood pressure control

In advanced CKD with eGFR <30 mL/min/1.73 m², the ADA 2026 identifies GLP-1 receptor agonists as preferred for glucose management because of their lower hypoglycemia risk and cardiovascular benefits.

18. Diabetes and Cardiovascular Disease

Cardiovascular disease is a major cause of morbidity and mortality in diabetes.

Management should include:

Blood pressure control
Lipid management
Smoking cessation
Physical activity
Weight management
Appropriate antiplatelet therapy when indicated
Use of glucose-lowering agents with proven cardiovascular benefit when appropriate

For people with type 2 diabetes and established or high-risk ASCVD, the ADA 2026 recommends incorporating a GLP-1 receptor agonist and/or SGLT2 inhibitor with demonstrated cardiovascular benefit, independent of HbA1c.

19. Blood Pressure Management

Blood pressure should be monitored regularly.

The ADA 2026 recommends pharmacologic treatment for confirmed office blood pressure ≥130/80 mmHg, with the individualized target determined according to the patient’s clinical circumstances.

In patients with diabetes and albuminuria or coronary artery disease, an ACE inhibitor or ARB is recommended as first-line antihypertensive therapy.

ACE inhibitors and ARBs should not be combined routinely.

20. Cholesterol and Statin Therapy

Lipid management is an essential part of diabetes care.

For adults aged 40–75 years with diabetes without ASCVD, the ADA 2026 recommends at least moderate-intensity statin therapy.

For patients at higher cardiovascular risk, high-intensity statin therapy is recommended to achieve a substantial LDL-C reduction and an LDL-C goal below 70 mg/dL (1.8 mmol/L) in the primary-prevention setting described by the guideline.

For people with diabetes and established ASCVD, the LDL-C goal is <55 mg/dL (1.4 mmol/L) with high-intensity lipid-lowering therapy and additional therapy when necessary.

21. Diabetes and Obesity

Weight management should be considered a distinct treatment goal, not simply a secondary consequence of glucose treatment.

For people with diabetes and overweight or obesity, treatment may include:

Nutrition intervention
Physical activity
Behavioral support
Anti-obesity pharmacotherapy
GLP-1 receptor agonists
Dual GIP/GLP-1 receptor agonists
Metabolic/bariatric surgery for appropriate candidates

The ADA 2026 specifically recommends prioritizing glucose-lowering medications that have beneficial effects on weight in people with diabetes and overweight or obesity.

22. Continuous Glucose Monitoring

Continuous glucose monitoring (CGM) has become an important component of modern diabetes management.

The ADA 2026 recommends CGM for adults with diabetes who use insulin and also supports CGM for selected patients using non-insulin therapies associated with hypoglycemia or when CGM can improve diabetes management.

CGM can provide information about:

Current glucose
Glucose trends
Time in range
Hypoglycemia
Hyperglycemia
Glycemic variability

For many adults using CGM, a time in range >70% is an appropriate goal.

23. Screening and Prevention of Diabetes Complications

Good diabetes treatment includes regular screening for complications.

Eye examination

People with type 2 diabetes should receive a comprehensive dilated eye examination at the time of diagnosis.

For type 1 diabetes, the initial comprehensive eye examination is generally recommended approximately five years after onset.

The frequency of subsequent examinations depends on the presence and severity of retinopathy.

Kidney screening

Assess:

eGFR
Urine albumin-to-creatinine ratio

The frequency depends on diabetes type, duration and kidney disease status.

Neuropathy

Peripheral neuropathy should be assessed:

At diagnosis of type 2 diabetes
Five years after diagnosis of type 1 diabetes
At least annually thereafter

The examination may include a 10-g monofilament test, vibration testing and assessment of pinprick or temperature sensation.

Foot examination

A comprehensive foot examination should be performed at least annually.

Patients should be taught to inspect their feet every day and seek medical attention promptly for:

Ulcers
Blisters
Redness
Swelling
New wounds
Skin breakdown
Signs of infection

High-risk patients require more frequent professional foot assessment.

24. Treatment of Diabetic Neuropathic Pain

For painful diabetic peripheral neuropathy, medications may include:

Gabapentinoids
Serotonin-norepinephrine reuptake inhibitors
Tricyclic antidepressants
Sodium-channel blockers

The ADA 2026 recommends these medication groups as initial pharmacologic options for painful diabetic neuropathy.

Routine use of opioids, including tramadol and tapentadol, is not recommended because of their potential harms.

25. Prevention and Management of Hypoglycemia

Hypoglycemia is an important treatment-related complication.

Symptoms may include:

Sweating
Tremor
Hunger
Palpitations
Dizziness
Confusion
Behavioral changes
Seizures
Loss of consciousness

Patients using insulin or medications that can cause hypoglycemia should be educated about prevention and treatment.

Medication regimens should be adjusted when recurrent hypoglycemia occurs.

CGM can be particularly useful for detecting and preventing hypoglycemia in appropriate patients.

26. Diabetes Treatment During Illness

Illness can significantly increase blood glucose and, particularly in insulin-deficient states, can precipitate diabetic ketoacidosis.

Patients should have a sick-day plan, including instructions regarding:

Glucose monitoring
Ketone testing when appropriate
Insulin continuation
Hydration
Medication adjustments
When to contact a healthcare professional
When emergency care is required

Patients with persistent vomiting, severe dehydration, altered consciousness, significant ketones or suspected DKA require urgent medical evaluation.

27. A Practical Approach to Type 2 Diabetes Treatment

A simplified approach is:

Step 1: Confirm diagnosis and assess the patient

Evaluate:

HbA1c
Glucose pattern
Weight/BMI
Blood pressure
Lipid profile
eGFR
Urine albumin
Cardiovascular disease
Heart failure
CKD
Obesity
Hypoglycemia risk
Diabetes complications

Step 2: Begin lifestyle intervention and diabetes education

Step 3: Start appropriate pharmacologic therapy

Do not automatically use the same drug for every patient.

Step 4: Identify cardiorenal priorities

ASCVD → consider GLP-1 RA and/or SGLT2 inhibitor with proven benefit
Heart failure → prioritize SGLT2 inhibitor with proven benefit
CKD → SGLT2 inhibitor and/or GLP-1 RA with demonstrated benefit
Obesity → prioritize therapies with meaningful weight-loss effects

Step 5: Reassess regularly

If treatment goals are not achieved, intensify therapy rather than allowing prolonged uncontrolled hyperglycemia.

Step 6: Monitor for complications

Regularly assess:

Eyes
Kidneys
Feet
Neuropathy
Cardiovascular risk
Lipids
Blood pressure

Frequently Asked Questions (FAQ)

1. What is the best medicine for type 2 diabetes?

There is no single best medicine for every patient.

Metformin remains an important option, but GLP-1 receptor agonists, dual GIP/GLP-1 receptor agonists and SGLT2 inhibitors may be preferred or prioritized when obesity, cardiovascular disease, heart failure or chronic kidney disease is present. Treatment should be individualized.

2. Should everyone with type 2 diabetes take metformin?

Not necessarily.

Metformin remains effective, inexpensive and widely used, but current guidelines emphasize selecting therapy according to the patient’s cardiovascular, kidney, weight and other clinical characteristics rather than automatically using metformin as the only first-line treatment.

3. When should insulin be started in type 2 diabetes?

Insulin may be necessary when hyperglycemia is severe, when there are symptoms or catabolic features, when ketosis is present, or when adequate glycemic control cannot be achieved with appropriate non-insulin therapy.

4. Can diabetes be cured?

Type 1 diabetes currently requires lifelong insulin replacement.

Type 2 diabetes can sometimes enter remission, particularly following substantial weight loss or metabolic surgery in appropriate patients. However, remission does not mean that lifelong follow-up is unnecessary.

5. Can a person with diabetes eat rice?

Yes.

People with diabetes do not necessarily need to completely eliminate rice. Portion size, carbohydrate quantity, food quality, meal composition and overall calorie intake are important.

For Cambodian patients, nutrition advice should take local dietary patterns into account rather than simply recommending unfamiliar Western foods.

6. Can people with diabetes eat fruit?

Yes. Whole fruit can generally be incorporated into a healthy eating pattern.

However, portion size and total carbohydrate intake matter. Fruit juice should generally be limited because it can provide a large amount of rapidly available carbohydrate without the same fiber and satiety as whole fruit.

7. Is HbA1c below 7% always necessary?

No.

An HbA1c <7% is appropriate for many nonpregnant adults, but targets should be individualized. More stringent or less stringent targets may be appropriate depending on age, comorbidities, hypoglycemia risk, functional status and treatment burden.

8. Can diabetes medication be stopped if blood sugar becomes normal?

Not without medical advice.

Normal glucose may occur because treatment is working. Stopping medication abruptly can result in hyperglycemia and, in insulin-deficient patients, potentially serious metabolic complications.

9. Are SGLT2 inhibitors only used to lower blood sugar?

No.

SGLT2 inhibitors can provide important cardiovascular and kidney benefits in appropriately selected people with type 2 diabetes, including patients with heart failure and CKD.

10. Are GLP-1 medications only for diabetes?

No.

Some GLP-1–based therapies are also used for obesity management and may provide cardiovascular or other metabolic benefits in appropriately selected patients.

11. How often should someone with diabetes have an eye examination?

People with type 2 diabetes should generally have a comprehensive eye examination at diagnosis. People with type 1 diabetes generally begin screening about five years after onset. Follow-up frequency depends on findings.

12. How often should the feet be checked?

A comprehensive foot examination should be performed at least annually, with more frequent examinations for patients with neuropathy, peripheral arterial disease, previous ulceration, amputation or other high-risk features.

Key Takeaways

Modern diabetes treatment is personalized rather than one-size-fits-all.

The most important principles are:

Set individualized glucose and HbA1c targets.
Use healthy nutrition, physical activity and diabetes education as the foundation of care.
Choose medications according to the patient’s cardiovascular, kidney and weight-related conditions—not glucose alone.
Use GLP-1–based therapy and/or SGLT2 inhibitors when indicated for cardiovascular or kidney risk reduction.
Consider weight management an important therapeutic goal.
Use insulin when insulin deficiency or severe hyperglycemia requires it.
Use CGM and diabetes technology when clinically appropriate.
Treat blood pressure and cholesterol aggressively according to individual cardiovascular risk.
Screen regularly for kidney disease, retinopathy, neuropathy and diabetic foot disease.
Avoid therapeutic inertia—treatment should be intensified when targets are not being achieved.

Effective diabetes management is therefore not simply about achieving a normal blood glucose level. It is about reducing long-term complications, protecting the heart and kidneys, maintaining healthy body weight, avoiding hypoglycemia and helping each patient achieve the best possible quality of life.

References

American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 8. Obesity and Weight Management for the Prevention and Treatment of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 11. Chronic Kidney Disease and Risk Management: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
American Diabetes Association Professional Practice Committee. 12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes—2026. Diabetes Care. 2026.
Holt RI, et al. The Management of Type 1 Diabetes in Adults. The Updated 2026 Consensus Report by the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care. 2026.
World Health Organization. Diabetes: Questions and Answers. Updated September 2026.
World Health Organization. The selection and use of essential medicines 2025. WHO Expert Committee on Selection and Use of Essential Medicines.

Medical disclaimer: This article is intended for general education and does not replace individualized medical assessment. Medication selection and dosing should be determined by a qualified healthcare professional based on the patient’s clinical condition, laboratory results, kidney and liver function, other medications and individual treatment goals.