Disease
A disease is a particular abnormal condition that adversely affects the structure or function of an organism. Diseases can be caused by various factors, including pathogens (like bacteria, viruses, fungi, and protozoa), genetic mutations, environmental factors, and lifestyle choices.
Human Diseases
It is divided into types Congenital and Acquired Diseases.
The Acquired disease is further divided into Communicable and Non- Communicable disease.
Communicable Disease
Communicable diseases, also known as infectious diseases, are illnesses caused by pathogens such as bacteria, viruses, fungi, and parasites. These diseases can be transmitted from one person to another, from animals to humans, or through the environment. They pose significant public health challenges due to their potential to spread rapidly and cause widespread illness.
Pathogen that cause communicable disease:
- Bacteria
- Virus
- Protozoa
- Fungi
- Helminth
Modes of Transmission of Communicable Diseases
Communicable Diseases: Pathogens, Classifications, and Modes of Transmission
The following table outlines common communicable diseases, their causative pathogens with classification, and modes of transmission:
| Disease | Pathogen | Classification | Modes of Transmission |
|---|---|---|---|
| Tuberculosis | Mycobacterium tuberculosis | Bacteria | Airborne (coughing, sneezing) |
| Malaria | Plasmodium species | Parasite | Vector-borne (Anopheles mosquitoes) |
| Cholera | Vibrio cholerae | Bacteria | Waterborne (contaminated water/food) |
| Influenza | Influenza virus | Virus | Airborne, direct contact |
| Hepatitis B | Hepatitis B virus | Virus | Bloodborne, sexual contact |
| Dengue | Dengue virus | Virus | Vector-borne (Aedes mosquitoes) |
| COVID-19 | SARS-CoV-2 | Virus | Airborne, direct contact |
| Measles | Measles morbillivirus | Virus | Airborne, direct contact |
| HIV/AIDS | Human immunodeficiency virus | Virus | Bloodborne, sexual contact, mother-to-child |
| Typhoid | Salmonella typhi | Bacteria | Waterborne, foodborne |
| Rabies | Rabies virus | Virus | Animal bites (saliva) |
| Polio | Poliovirus | Virus | Fecal-oral, contaminated water/food |
| Tetanus | Clostridium tetani | Bacteria | Contaminated wounds |
| Leptospirosis | Leptospira species | Bacteria | Waterborne (contaminated water) |
| Hepatitis A | Hepatitis A virus | Virus | Fecal-oral, contaminated food/water |
Non Communicable Diseases
Non-communicable diseases (NCDs), also known as chronic diseases, are medical conditions that are not caused by infectious agents and cannot be transmitted from person to person. These diseases typically progress slowly and persist for long periods, often leading to long-term health issues and disabilities. NCDs are a major public health concern globally, accounting for a significant portion of mortality and morbidity.
It is further divided into Deficiency disease and Degenerative disease.
Deficiency Disease
| Disease | Cause | Symptoms | Cure/Prevention |
|---|---|---|---|
| Scurvy | Vitamin C deficiency | Fatigue, swollen gums, joint pain | Increase intake of vitamin C-rich foods like citrus fruits, tomatoes, and leafy greens |
| Rickets | Vitamin D deficiency | Soft, weak bones, skeletal deformities | Ensure sufficient sunlight exposure and consume foods rich in vitamin D like fortified dairy products and fish |
| Beriberi | Vitamin B1 (Thiamine) deficiency | Weakness, nerve degeneration, heart issues | Include whole grains, legumes, nuts, and seeds in diet |
| Pellagra | Niacin (Vitamin B3) deficiency | Diarrhea, dermatitis, dementia | Intake of niacin-rich foods such as poultry, fish, and whole grains |
| Anemia | Iron deficiency | Fatigue, paleness, shortness of breath | Consume iron-rich foods like spinach, red meat, and iron supplements if needed |
| Night Blindness | Vitamin A deficiency | Difficulty seeing in low light | Increase intake of vitamin A-rich foods such as carrots, sweet potatoes, and liver |
| Goiter | Iodine deficiency | Swelling in the neck, thyroid dysfunction | Use iodized salt and consume iodine-rich foods like seafood and dairy products |
Degenerative disease
Here’s a table summarizing some common degenerative diseases, their causes, symptoms, and potential treatments:
| Disease | Cause | Symptoms | Potential Cure/Treatment |
|---|---|---|---|
| Osteoarthritis | Wear and tear of cartilage | Joint pain, stiffness, swelling, reduced range of motion | Pain relief medications, physical therapy, joint replacement surgery |
| Alzheimer’s Disease | Genetic factors, brain changes | Memory loss, confusion, difficulty with coordination, mood swings | Medications to manage symptoms, supportive care |
| Parkinson’s Disease | Loss of dopamine-producing cells | Tremors, stiffness, slowness of movement, impaired balance | Medications, physical therapy, deep brain stimulation |
| Diabetes (Type 2) | Insulin resistance, genetic factors | Increased thirst, frequent urination, fatigue, blurred vision | Lifestyle changes, medications, insulin therapy |
| Chronic Obstructive Pulmonary Disease (COPD) | Smoking, environmental factors | Shortness of breath, chronic cough, wheezing, chest tightness | Bronchodilators, steroids, oxygen therapy, pulmonary rehabilitation |
| Cardiovascular Disease | High blood pressure, cholesterol, smoking | Chest pain, shortness of breath, heart attack, stroke | Lifestyle changes, medications, surgery (e.g., angioplasty) |
| Multiple Sclerosis (MS) | Immune system attacking nerve cells | Muscle weakness, coordination problems, vision issues, cognitive changes | Medications to manage symptoms, physical therapy, disease-modifying therapies |
Deficiency
It is nutrient deficiency such as Vitamin, Proteins etc.
Degenerative disease
- Heart
- Brain
- Digestive
- Lungs
- Kidney
- Eye
Diseases Caused by Microbes
1. Bacteria :
Here’s a table listing common bacterial diseases in humans along with their symptoms:
| Disease | Causative Bacteria | Symptoms |
|---|---|---|
| Tuberculosis (TB) | Mycobacterium tuberculosis | Persistent cough, fever, night sweats, weight loss, fatigue, chest pain. |
| Cholera | Vibrio cholerae | Severe diarrhea, dehydration, abdominal cramps, nausea, vomiting. |
| Typhoid Fever | Salmonella typhi | High fever, weakness, stomach pain, loss of appetite, rash. |
| Pneumonia | Streptococcus pneumoniae | Cough with phlegm, fever, chills, shortness of breath, chest pain. |
| Strep Throat | Streptococcus pyogenes | Sore throat, fever, red/swollen tonsils, difficulty swallowing. |
| Plague | Yersinia pestis | Swollen lymph nodes, fever, chills, weakness, headache. |
| Diphtheria | Corynebacterium diphtheriae | Sore throat, fever, swollen glands, difficulty breathing, thick throat coating. |
| Tetanus (Lockjaw) | Clostridium tetani | Muscle stiffness, spasms, difficulty swallowing, fever, sweating. |
| Leprosy (Hansen’s Disease) | Mycobacterium leprae | Skin lesions, numbness, muscle weakness, nerve damage. |
| Whooping Cough (Pertussis) | Bordetella pertussis | Severe coughing fits, “whooping” sound during breath, vomiting after cough. |
| Botulism | Clostridium botulinum | Muscle weakness, difficulty speaking/swallowing, blurred vision, paralysis. |
| Gonorrhea | Neisseria gonorrhoeae | Painful urination, genital discharge, pelvic pain (in females). |
| Syphilis | Treponema pallidum | Sores, rashes, fever, swollen lymph nodes, organ damage (late stages). |
| Meningitis | Neisseria meningitidis | Severe headache, stiff neck, fever, nausea, sensitivity to light, confusion. |
| Anthrax | Bacillus anthracis | Skin sores, fever, cough, difficulty breathing, nausea (depending on form). |
2.Virus Diseases
Here’s a table of common viral diseases in humans and their associated symptoms:
| Disease | Causative Virus | Symptoms |
|---|---|---|
| Common Cold | Rhinovirus | Runny nose, sneezing, sore throat, mild cough, congestion, fatigue. |
| Influenza (Flu) | Influenza virus | Fever, chills, cough, sore throat, body aches, fatigue, headache. |
| COVID-19 | SARS-CoV-2 | Fever, cough, fatigue, loss of taste/smell, shortness of breath, aches. |
| HIV/AIDS | Human Immunodeficiency Virus | Weak immune system, weight loss, fever, night sweats, opportunistic infections. |
| Hepatitis A | Hepatitis A virus (HAV) | Fatigue, nausea, abdominal pain, jaundice, dark urine, loss of appetite. |
| Hepatitis B | Hepatitis B virus (HBV) | Jaundice, fatigue, abdominal pain, joint pain, dark urine, fever. |
| Hepatitis C | Hepatitis C virus (HCV) | Often asymptomatic, but can include fatigue, jaundice, liver damage symptoms. |
| Chickenpox | Varicella-zoster virus | Itchy rash, fever, fatigue, loss of appetite, fluid-filled blisters. |
| Measles | Measles virus | High fever, rash, cough, runny nose, conjunctivitis, white spots in mouth. |
| Mumps | Mumps virus | Swollen salivary glands, fever, headache, fatigue, muscle aches. |
| Rubella (German Measles) | Rubella virus | Mild fever, rash, swollen lymph nodes, joint pain, cold-like symptoms. |
| Polio | Poliovirus | Fever, sore throat, headache, stiffness, muscle weakness, paralysis (in severe cases). |
| Rabies | Rabies virus | Fever, anxiety, confusion, difficulty swallowing, hydrophobia, paralysis (late stage). |
| Dengue Fever | Dengue virus | High fever, severe headache, joint and muscle pain, rash, bleeding (severe cases). |
| Zika Virus Disease | Zika virus | Fever, rash, joint pain, conjunctivitis, muscle pain, headache. |
| Ebola Virus Disease | Ebola virus | Fever, severe headache, muscle pain, weakness, vomiting, diarrhea, bleeding. |
| Smallpox | Variola virus | High fever, fatigue, distinctive rash with raised blisters. |
| Herpes (Oral/Genital) | Herpes simplex virus (HSV) | Painful sores, blisters, itching, fever, swollen lymph nodes. |
3.Fungal Diseases
Here’s a table of common fungal diseases in humans and their associated symptoms:
| Disease | Causative Fungi | Symptoms |
|---|---|---|
| Athlete’s Foot | Trichophyton species | Itchy, red, scaly, or peeling skin on the feet, particularly between toes. |
| Ringworm (Tinea) | Trichophyton, Microsporum, Epidermophyton | Circular, red, itchy, and scaly patches on the skin, with a clear center. |
| Candidiasis (Thrush) | Candida albicans | White patches in the mouth, vaginal itching, discharge, redness, or burning. |
| Aspergillosis | Aspergillus species | Cough, fever, chest pain, difficulty breathing (invasive type). |
| Histoplasmosis | Histoplasma capsulatum | Fever, cough, chest pain, fatigue, body aches (often mild). |
| Cryptococcosis | Cryptococcus neoformans | Headache, fever, confusion, neck stiffness (common in immunocompromised individuals). |
| Blastomycosis | Blastomyces dermatitidis | Fever, cough, fatigue, chest pain, skin lesions. |
| Pityriasis Versicolor | Malassezia species | Discolored patches of skin, mild itching, scaling. |
| Sporotrichosis (Rose Gardener’s Disease) | Sporothrix schenckii | Skin ulcers, red nodules, swollen lymph nodes (cutaneous form). |
| Valley Fever (Coccidioidomycosis) | Coccidioides immitis | Fever, chest pain, cough, fatigue, rash (in severe cases, spreads to organs). |
| Fungal Nail Infections | Trichophyton species | Thickened, discolored, brittle nails, often with debris buildup. |
| Mucormycosis (Black Fungus) | Rhizopus and Mucor species | Facial pain, nasal congestion, blackened tissue in the nose/mouth (in severe cases). |
| Penicilliosis | Talaromyces marneffei | Fever, skin lesions, cough, and weight loss (common in immunocompromised individuals). |
| Chromycosis (Chromoblastomycosis) | Various fungi (Fonsecaea, Cladophialophora) | Warty skin lesions, slow progression to chronic infection. |
4.Protozoa Diseases
Here’s a table of common protozoan diseases in humans and their associated symptoms:
| Disease | Causative Protozoan | Symptoms |
|---|---|---|
| Malaria | Plasmodium species (P. falciparum, P. vivax, P. malariae, P. ovale) | Fever, chills, sweating, headache, muscle pain, fatigue, nausea, vomiting. |
| Amoebiasis | Entamoeba histolytica | Abdominal pain, diarrhea (sometimes with blood), fever, weight loss. |
| Giardiasis | Giardia lamblia | Diarrhea, abdominal cramps, bloating, gas, nausea, fatigue, weight loss. |
| Leishmaniasis | Leishmania species | Skin sores, fever, weight loss, swollen spleen and liver (visceral form). |
| Trypanosomiasis (Sleeping Sickness) | Trypanosoma brucei | Fever, headache, joint pain, swollen lymph nodes, confusion, sleep disturbances. |
| Chagas Disease | Trypanosoma cruzi | Fever, fatigue, swelling at infection site, heart and digestive complications (chronic stage). |
| Toxoplasmosis | Toxoplasma gondii | Flu-like symptoms, swollen lymph nodes, muscle aches (severe in immunocompromised individuals). |
| Cryptosporidiosis | Cryptosporidium species | Watery diarrhea, stomach cramps, nausea, fever, dehydration. |
| Babesiosis | Babesia species | Fever, chills, fatigue, muscle aches, nausea, dark urine. |
| Trichomoniasis | Trichomonas vaginalis | Genital itching, burning during urination, vaginal or penile discharge. |
| Balantidiasis | Balantidium coli | Diarrhea (sometimes with blood), abdominal pain, nausea, vomiting, weight loss. |
| Kala-Azar (Visceral Leishmaniasis) | Leishmania donovani | Fever, weight loss, darkening of the skin, enlarged spleen and liver, anemia. |
| Primary Amoebic Meningoencephalitis (PAM) | Naegleria fowleri | Severe headache, fever, nausea, stiff neck, confusion, seizures, coma (rare but fatal). |
| Cyclosporiasis | Cyclospora cayetanensis | Watery diarrhea, abdominal pain, nausea, fatigue, weight loss. |