Respiratory and circulatory disorders
Respiratory disorders
The lungs bring in oxygen and push out carbon dioxide.
- Asthma: airways narrow and swell; wheeze and breathlessness.
- Pneumonia: infection fills lung air sacs with fluid; fever, cough, fast breathing.
- Tuberculosis (TB): long-lasting bacterial lung infection.
- COPD: long-term lung damage, mostly from smoking.
Circulatory disorders
The heart and vessels move blood.
- Hypertension: blood pressure stays high (above about 140/90 mmHg on repeat checks).
- Coronary artery disease and heart attack: the heart muscle's own vessels block.
- Stroke: a brain vessel blocks or bursts.
- Varicose veins, heart failure.
Intake, digestion, absorption and metabolism
Food has to be eaten, digested, absorbed and used. Trouble can come at every stage.
- Intake: difficulty swallowing, anorexia (not eating), obesity (eating too much).
- Digestion: peptic ulcer, gastritis, gallstones, diarrhoea, constipation, jaundice from liver disease (hepatitis).
- Absorption: coeliac disease (gluten damages the gut lining), lactose intolerance.
- Metabolism: diabetes, gout, high cholesterol, malnutrition and vitamin lack (rickets, scurvy, night blindness).
Disorders of internal regulation
Hormones from glands (thyroid, pancreas, adrenal, pituitary) keep the inside steady (homeostasis).
- Diabetes: pancreas makes too little insulin (type 1) or the body does not respond to it (type 2).
- Hypothyroidism: slow thyroid, tired and cold, weight gain. Hyperthyroidism: fast thyroid, thin, sweaty, fast heart.
- Goitre: swollen thyroid, often from lack of iodine.
- Growth disorders from the pituitary, and Cushing's or Addison's disease of the adrenal gland.
Haematopoietic (blood-making) and immune disorders
Blood disorders
Blood cells are made in the bone marrow.
- Anaemia: too little haemoglobin or red cells. Tired, pale, breathless. Iron lack is the commonest cause.
- Leukaemia: cancer of white-cell making.
- Haemophilia: blood does not clot well. Thalassaemia and sickle cell disease: inherited red-cell disorders.
Immune disorders
- Allergy: over-reaction to a harmless trigger (pollen, dust, food).
- Autoimmune disease: defence attacks the self (type 1 diabetes, rheumatoid arthritis).
- Immune deficiency: weak defence (HIV/AIDS).
Neurological, motor and mental disorders
Neurological disorders
- Stroke, epilepsy (sudden bursts of brain activity cause seizures), migraine, meningitis, Parkinson's disease, dementia.
Motor function disorders
- Fracture: broken bone. Osteoporosis: thin, weak bones. Arthritis: painful stiff joints. Muscular dystrophy: muscles weaken. Paralysis from spinal or nerve injury.
Mental dysfunction
- Depression (long low mood), anxiety disorders (strong fear or worry), schizophrenia, bipolar disorder. They are real health conditions, treatable with talking therapy, medicine and support.
Excretory and reproductive disorders
Excretory disorders
Kidneys filter blood and make urine.
- Kidney stones: hard crystals that cause sharp pain. Urinary tract infection (UTI): burning urine. Nephritis: swollen kidney filters. Kidney failure: kidneys stop cleaning the blood, so dialysis or a transplant may be needed.
Reproductive disorders
- Infertility (trouble having a baby), sexually transmitted infections (prevented by safe practice and tests), PCOS, endometriosis, prostate enlargement, and cancers of reproductive organs found by screening.
Try it
Match your family. Ask older people which long-term condition they have (for example BP, sugar, joint pain). For each, say which function in the 3D is the one affected.
In the 3D: use the last step. Choose "Hormones" and slide the disorder to 80%. Then try "Nerves". Which shows a bigger drop in working level? Why can any drop matter?
Key formulas and definitions
- Eleven functions: breathing · circulation · intake/digestion/metabolism · regulation · blood · defence · nerves · movement · excretion · reproduction · mind
- Respiratory: asthma, pneumonia, TB · Circulatory: hypertension, heart attack, stroke
- Regulation: diabetes, thyroid disease · Blood: anaemia, leukaemia, haemophilia
- Immune: allergy, autoimmune, immunodeficiency · Excretory: stones, UTI, kidney failure
- Working level = 100% − disorder level (as in the 3D slider)
Worked examples
1. A child wheezes in dusty air and the breathing tubes narrow. Which function and which disorder?
Breathing (respiratory) function; the disorder is asthma, in which airways narrow and swell.
2. A woman is pale, tired and breathless, and a test shows low haemoglobin. Name the disorder and its common cause.
Anaemia. Iron lack in food is the most common cause.
3. In the 3D the disorder slider on "Waste removal" is at 70%. What is the working level? What could the problem be?
Working level = 100 − 70 = 30%. Possible problem: kidney failure or stones blocking the way; the person may need dialysis if kidneys cannot clean the blood.
4. Sort into the right function: epilepsy, osteoporosis, hypothyroidism, hepatitis.
Epilepsy: nerves. Osteoporosis: movement (bones). Hypothyroidism: internal regulation (hormones). Hepatitis: digestion and metabolism (liver).
Common mistakes
- Thinking a mental disorder is a weakness or "just in the head". It is a real health condition with causes and treatment.
- Mixing diabetes types. Type 1: little insulin; type 2: body responds poorly to insulin.
- Thinking allergy is an infection. It is an immune over-reaction to a harmless thing and does not spread.
- Thinking high blood pressure always has symptoms. Often there are none, so it must be measured.