What can cause disease?
1. Infectious agents:- Bacteria: Organisms that can cause infections such as pneumonia, tuberculosis, and food poisoning.
- Viruses: Agents that invade and replicate within the cells of living organisms, leading to diseases such as influenza, measles, and AIDS.
- Fungi: Organisms that can cause infections known as mycoses, including athlete's foot, ringworm, and Candida.
2. Genetic disorders:
- Inherited genetic disorders: Diseases caused by mutations in the genetic material passed from parents to offspring, such as cystic fibrosis and sickle cell anemia.
- Acquired genetic disorders: Diseases resulting from genetic mutations that occur spontaneously, such as certain types of cancer.
3. Environmental factors:
- Air pollution: Exposure to pollutants like particulate matter, ozone, and nitrogen dioxide can increase the risk of respiratory diseases, heart disease, and cancer.
- Water pollution: Contaminated water sources can transmit infectious diseases like diarrhea, cholera, and typhoid fever.
- Chemical exposure: Chemicals used in agriculture, industry, and household products can lead to poisoning, allergies, and chronic diseases.
4. Nutritional deficiencies:
- Undernutrition: Lack of sufficient calories and nutrients, leading to diseases like kwashiorkor, beriberi, and scurvy.
- Micronutrient deficiencies: Deficiencies in essential vitamins, minerals, or trace elements, such as iron deficiency anemia, goiter, and rickets.
5. Lifestyle factors:
- Tobacco smoking: Increases the risk of lung cancer, cardiovascular diseases, and respiratory problems.
- Alcohol misuse: Excessive alcohol consumption can damage the liver, heart, brain, and other organs.
- Unhealthy diet: Diets high in saturated and trans fats, sugar, and salt contribute to conditions like obesity, type 2 diabetes, and heart disease.
- Lack of physical activity: Sedentary lifestyles can increase the likelihood of chronic diseases and overall poor health.
6. Autoimmune diseases:
- Diseases in which the body's immune system mistakenly attacks its own tissues, leading to inflammation and tissue damage. Examples include rheumatoid arthritis, lupus, and multiple sclerosis.