2.5 Common Diseases and Conditions
Key Takeaways
- The "3 Ps" of diabetes are polyuria (excessive urination), polydipsia (excessive thirst), and polyphagia (excessive hunger)
- Hypertension is classified as Stage 1 (130-139/80-89) and Stage 2 (140+/90+); a hypertensive crisis is systolic >180 and/or diastolic >120
- Asthma is a chronic inflammatory airway disease with reversible bronchospasm; managed with controller medications (inhaled corticosteroids) and rescue inhalers (albuterol)
- Heart disease risk factors include hypertension, high cholesterol, diabetes, smoking, obesity, sedentary lifestyle, family history, and age
- Cancer warning signs follow the CAUTION acronym: Change in bowel/bladder habits, A sore that doesn't heal, Unusual bleeding, Thickening or lump, Indigestion/difficulty swallowing, Obvious change in wart/mole, Nagging cough/hoarseness
- Infectious diseases follow the chain of infection and are controlled through vaccination, hand hygiene, isolation precautions, and antimicrobial therapy
Last updated: March 2026
Common Diseases and Conditions
Medical assistants must understand common diseases and conditions to effectively support patient care, education, and clinical decision-making.
Diabetes Mellitus
| Feature | Type 1 | Type 2 |
|---|---|---|
| Cause | Autoimmune destruction of beta cells | Insulin resistance ± decreased production |
| Onset | Usually childhood/adolescence | Usually adulthood (increasing in youth) |
| Body type | Often thin/normal weight | Often overweight/obese |
| Insulin | Always required (no insulin production) | May or may not require insulin |
| Treatment | Insulin injections, glucose monitoring | Lifestyle changes, oral meds, possibly insulin |
| DKA risk | High (diabetic ketoacidosis) | Low (more likely hyperosmolar state) |
The "3 Ps" of Diabetes:
- Polyuria — Excessive urination (glucose pulls water into urine)
- Polydipsia — Excessive thirst (dehydration from polyuria)
- Polyphagia — Excessive hunger (cells cannot use glucose for energy)
Diabetic Emergencies:
| Emergency | Blood Glucose | Symptoms | Treatment |
|---|---|---|---|
| Hypoglycemia | <70 mg/dL | Shaking, sweating, confusion, rapid heartbeat | Conscious: 15g fast-acting sugar; recheck in 15 min |
| Hyperglycemia | >250 mg/dL | Thirst, frequent urination, fatigue, blurred vision | Follow provider orders; may need insulin adjustment |
| DKA | Very high; ketones present | Fruity breath, Kussmaul breathing, nausea, abdominal pain | Medical emergency — call 911 |
Cardiovascular Diseases
Coronary Artery Disease (CAD):
- Atherosclerosis (plaque buildup) narrows coronary arteries
- Can lead to angina (chest pain) or myocardial infarction (heart attack)
- Risk factors: hypertension, high cholesterol, diabetes, smoking, obesity, family history
Heart Failure:
- Heart cannot pump blood effectively
- Symptoms: shortness of breath, edema (swelling), fatigue, weight gain
- Left-sided: pulmonary congestion (fluid in lungs)
- Right-sided: peripheral edema (swelling in legs/feet/abdomen)
Respiratory Diseases
| Disease | Description | Key Features |
|---|---|---|
| Asthma | Chronic airway inflammation with reversible bronchospasm | Wheezing, cough, chest tightness; triggered by allergens, exercise, cold air |
| COPD | Chronic obstructive pulmonary disease (emphysema + chronic bronchitis) | Progressive, irreversible airflow limitation; most commonly caused by smoking |
| Pneumonia | Infection of lung tissue | Fever, productive cough, dyspnea; bacterial, viral, or fungal |
| TB | Tuberculosis (Mycobacterium tuberculosis) | Cough >3 weeks, night sweats, weight loss; airborne transmission |
Cancer Warning Signs (CAUTION)
| Letter | Warning Sign |
|---|---|
| C | Change in bowel or bladder habits |
| A | A sore that does not heal |
| U | Unusual bleeding or discharge |
| T | Thickening or lump in breast or elsewhere |
| I | Indigestion or difficulty swallowing |
| O | Obvious change in a wart or mole |
| N | Nagging cough or hoarseness |
Test Your Knowledge
The "3 Ps" of diabetes mellitus are:
A
B
C
D
Test Your Knowledge
Which type of diabetes requires insulin injections from the time of diagnosis?
A
B
C
D
Test Your Knowledge
In the CAUTION cancer warning signs acronym, the "U" stands for:
A
B
C
D