2 Diabetes Mellitus and Nursing Care

Diabetes and its major types

Diabetes mellitus is a group of conditions in which blood glucose remains elevated because the body produces too little insulin, cannot use insulin effectively, or both. Insulin allows glucose to enter cells for energy. When insulin is absent or ineffective, glucose accumulates in the bloodstream.

The major types differ in their causes and treatment needs:

• Type 1 diabetes: Immune-mediated destruction of insulin-producing pancreatic beta cells leads to little or no insulin production. Insulin is essential for survival.

• Type 2 diabetes: Insulin resistance and a progressive inability of the pancreas to produce enough insulin cause hyperglycemia. Management may include changes to nutrition and activity, noninsulin medications, insulin, or combinations of these approaches.

• Gestational diabetes: Diabetes first diagnosed during pregnancy. It often resolves after birth but increases future risk of type 2 diabetes.

• Other specific types: Less common causes include single-gene conditions, pancreatic disease or surgery, and certain medications.

Assessment and glucose monitoring

Common symptoms of hyperglycemia include frequent urination, increased thirst, fatigue, blurred vision, and sometimes unexplained weight loss. Nursing assessment includes symptoms, medication use, food intake, activity, hydration, glucose records, and barriers to care.

A1C estimates average glucose over roughly the prior $2\text{–}3$ months. Finger-stick blood glucose and continuous glucose monitoring (CGM) provide information about current levels and patterns. Monitoring frequency depends on the treatment plan and the person’s needs. For example, a person using mealtime insulin may check or review glucose before meals to guide decisions according to their prescribed plan.

CGM shows glucose trends and alerts. Users should follow device instructions and confirm readings when symptoms do not match the sensor or when the care plan calls for confirmation.

For many nonpregnant adults, an individualized A1C goal is near $<7\%$, but this is not a universal target. The usual CGM time-in-range band identified for many adults is $70\text{–}180\text{ mg/dL}$. Targets should be individualized to health, hypoglycemia risk, and patient preferences.

Medication and insulin management

Medication selection depends on diabetes type, glucose goals, other health conditions, risk of low glucose, adverse effects, cost, access, and patient preferences. Type 1 diabetes requires insulin. Type 2 diabetes treatment may include several medication classes, some oral and others injectable. Choices are individualized; certain medicines are selected for heart or kidney benefits as well as glucose lowering.

Insulin plans may combine different roles:

• Basal insulin covers glucose needs between meals and overnight.

• Prandial (mealtime) insulin covers food-related glucose rises.

• Correction insulin addresses glucose above a prescribed target when included in the person’s plan.

For safe administration, verify the prescribed insulin, dose, timing, route, and glucose and meal context. Use the correct device, and document administration and response. Teach patients not to change doses or stop insulin without following their individualized instructions or contacting their care team.

Rotate injection sites within the recommended area. Repeatedly injecting the same spot can cause tissue changes and interfere with absorption. Store insulin as directed for the specific product.

Responding to acute glucose problems

A glucose level below $70\text{ mg/dL}$ is an alert value. Symptoms may include sweating, shakiness, hunger, palpitations, dizziness, irritability, or confusion. Severe hypoglycemia can cause seizure or loss of consciousness.

If the person is awake and can swallow, give $15\text{ g}$ of fast-acting carbohydrate, recheck in $15$ minutes, and repeat if the glucose is still low. For example, a conscious patient with a glucose reading of $62\text{ mg/dL}$ should receive $15\text{ g}$ of fast-acting carbohydrate, followed by a recheck in $15$ minutes and another treatment if still low.

If the person is unconscious or cannot safely swallow, do not give food or drink by mouth. Use prescribed glucagon if available and activate emergency help. Recurrent or severe episodes should prompt a review of the treatment plan.

Hyperglycemia and sick-day care

Illness, infection, missed medication, or other stressors can raise glucose. Follow the person’s sick-day plan, monitor more often as directed, maintain fluids when possible, and check ketones when instructed—especially for people with type 1 diabetes or those at risk of ketoacidosis. Do not stop basal insulin in type 1 diabetes without clinical direction.

Seek urgent care for breathing difficulty, persistent vomiting or inability to keep fluids down, significant ketones, or worsening mental status.

Preventing long-term complications

Persistent hyperglycemia increases the risk of cardiovascular disease and stroke, kidney disease, eye disease, and nerve damage. Neuropathy and poor circulation can contribute to unnoticed foot injury and ulcers.

Prevention and early detection include individualized glucose management, blood pressure and lipid care, scheduled eye and kidney screening, regular foot assessment, and daily inspection of the feet. Report a new wound, redness, swelling, or skin breakdown promptly.

Nursing care and self-management education

Nursing care combines assessment, safe medication administration, monitoring, complication prevention, and collaborative education. Use clear, nonjudgmental communication. Assess the person’s ability and resources to carry out the plan, including vision, dexterity, health literacy, food access, medication affordability, and support at home. Arrange diabetes self-management education and support (DSMES) when appropriate.

Help the patient practice skills rather than relying on written instructions alone. Education commonly addresses:

• How and when to monitor glucose and record or share results.

• Medication purpose, timing, administration, storage, and what to do about missed doses according to the prescribed plan.

• How to recognize and treat low glucose, the importance of carrying a fast-acting glucose source, and ensuring close contacts know how to respond to severe hypoglycemia.

• Meal planning that fits the person’s culture, preferences, and medication schedule; regular physical activity; and avoiding tobacco.

• Sick-day instructions, foot checks, and the importance of routine eye, kidney, dental, and cardiovascular care.

For example, a patient using fixed mealtime insulin reports skipping lunch during a busy workday. The nurse explores the reason, reviews the patient’s individualized instructions for missed meals and insulin, checks access to glucose and food, and collaborates with the care team on a safer plan. The nurse does not invent a dose adjustment.