Health literacy — the ability to understand and use health information to make informed decisions — is one of the most powerful determinants of health outcomes. This glossary explains the most important health and medical terms in plain, accessible language.
A – D
Anaemia — Insufficient healthy red blood cells or haemoglobin to carry adequate oxygen. Causes: iron deficiency, folate deficiency, sickle cell disease, malaria. Symptoms: fatigue, pallor, shortness of breath.
Antibiotic — Medicine that kills or stops bacterial growth. Does NOT work against viruses (colds, flu). Overuse drives antimicrobial resistance (AMR) — one of the greatest global health threats.
Antenatal care (ANC) — Healthcare received during pregnancy. WHO recommends at least 8 visits. Monitors mother and baby, detects complications, and delivers essential interventions.
BMI (Body Mass Index) — Weight (kg) divided by height squared (m²). Underweight: below 18.5; Normal: 18.5–24.9; Overweight: 25–29.9; Obese: 30+. Waist circumference is often a better health risk indicator.
Blood pressure — Force of blood on artery walls in mmHg. Normal: below 120/80. Hypertension: 130/80 or above.
Chronic disease — Disease persisting over 3+ months, typically managed rather than cured. Examples: diabetes, hypertension, asthma, HIV.
Dehydration — Body loses more fluid than it takes in. Severe dehydration is a medical emergency especially in children with diarrhoea or vomiting.
E – H
Endemic — Disease consistently present in a geographic area. Malaria is endemic in most of sub-Saharan Africa.
Epidemic — Sudden increase in disease cases above what is normally expected in a defined area or season.
Fasting blood glucose — Blood sugar measured after 8+ hours without food. Normal: below 5.6 mmol/L; Prediabetes: 5.6–6.9 mmol/L; Diabetes: 7.0 mmol/L or above.
Genotype — Genetic constitution. In African context, commonly refers to haemoglobin genotype: AA (normal), AS (sickle trait/carrier), SS (sickle cell disease).
HbA1c — Blood test reflecting average glucose over past 2–3 months. Normal: below 5.7%; Prediabetes: 5.7–6.4%; Diabetes: 6.5%+.
Hypertension — Blood pressure of 130/80 or above; the “silent killer” causing no symptoms until it damages heart, brain, or kidneys.
Hypoglycaemia — Blood glucose below 3.9 mmol/L. Causes shakiness, sweating, confusion; a medical emergency in people on insulin.
I – Z
Inflammation — Protective body response to injury or infection. Chronic low-grade inflammation underlies heart disease, diabetes, and cancer.
Microbiome — Community of microorganisms in and on the body, primarily the gut. Diverse, balanced gut microbiome supports immune function, mental health, and metabolic health.
Non-communicable disease (NCD) — Disease not spread person-to-person: diabetes, hypertension, heart disease, cancer. Responsible for 74% of all deaths globally; rising rapidly in Africa.
Pathogen — Microorganism (bacterium, virus, fungus, parasite) that causes disease.
Probiotic — Live microorganisms that, when consumed adequately, benefit gut health. Found in yoghurt, amasi, ogi, and dawadawa.
Sepsis — Life-threatening emergency where the body’s infection response damages its own tissues. Signs: fever or low temperature, rapid heart rate and breathing, confusion. Requires immediate emergency treatment.
Triage — Prioritising patients for treatment based on urgency. Used in emergency settings to ensure most critical patients receive care first.
Vector — Organism transmitting a pathogen between hosts. Mosquitoes transmit malaria, dengue, and yellow fever; tsetse flies transmit sleeping sickness.
Viral load — Amount of virus in bodily fluid. In HIV, undetectable viral load means the virus cannot be sexually transmitted and treatment is working.
Zoonosis — Disease transmissible from animals to humans. Examples: rabies, Ebola, monkeypox. Avoid contact with wild or sick animals; practise food safety.
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Disclaimer: This glossary is for general educational purposes only. For personalised medical advice or treatment, consult a qualified healthcare professional.
