Non-infectious Diseases — Revision Notes

⚡ 30-Second Revision

Non-infectious Diseases (NCDs): — Not contagious, not caused by pathogens.
Causes: — Genetic, lifestyle, environmental, age.
Key Examples:

- Cancer: Uncontrolled cell growth. Carcinogens: UV, tobacco, HPV. - Diabetes: - Type 1: Autoimmune, no insulin. - Type 2: Insulin resistance/deficiency, lifestyle-linked. - Allergies: Hypersensitivity to allergens (pollen, dust).

IgE, mast cells, histamine. - Asthma: Chronic airway inflammation, triggered by allergens/irritants. - Autoimmune: Immune system attacks self (e.g., Rheumatoid Arthritis, Type 1 Diabetes). - Deficiency: Lack of nutrients (e.

g., Vitamin C $\rightarrow$ Scurvy; Vitamin D $\rightarrow$ Rickets; Iron $\rightarrow$ Anemia).

Prevention: — Healthy lifestyle, avoid carcinogens/allergens, early detection.

2-Minute Revision

Non-infectious diseases (NCDs) are conditions that cannot be transmitted between individuals, as they are not caused by infectious agents. Their origins are diverse, stemming from genetic predispositions, lifestyle choices, environmental exposures, and the aging process. Key NCDs for NEET include Cancer, Diabetes Mellitus, Allergies, Asthma, Autoimmune disorders, and Deficiency diseases.

Cancer involves uncontrolled cell proliferation, often initiated by carcinogens like UV radiation, tobacco smoke, or certain viruses (e.g., HPV). Diabetes has two main types: Type 1, an autoimmune condition leading to absolute insulin deficiency, and Type 2, characterized by insulin resistance and often linked to obesity and inactivity.

Allergies are hypersensitivity reactions where the immune system overreacts to harmless allergens, mediated by IgE antibodies and histamine release from mast cells. Asthma is a chronic inflammatory airway disease, often triggered by allergens.

Autoimmune diseases occur when the immune system attacks the body's own tissues, such as in Rheumatoid Arthritis. Deficiency diseases result from inadequate intake of essential nutrients, like Scurvy (Vitamin C) or Rickets (Vitamin D).

Prevention largely focuses on adopting healthy lifestyles and minimizing exposure to known risk factors.

5-Minute Revision

Non-infectious diseases (NCDs) are a critical component of human health, distinct from infectious diseases because they are non-transmissible and not caused by pathogens. Their etiology is multifactorial, encompassing genetic, lifestyle, environmental, and age-related factors.

Cancer is characterized by uncontrolled cell growth and metastasis. Carcinogens, agents that cause cancer, can be physical (e.g., UV radiation causing skin cancer), chemical (e.g., tobacco smoke causing lung cancer), or biological (e.g., Human Papillomavirus causing cervical cancer). Treatment involves surgery, radiotherapy (using radiation to kill cancer cells), chemotherapy (drugs targeting rapidly dividing cells), and immunotherapy (boosting the body's immune response).

Diabetes Mellitus is a metabolic disorder of glucose regulation. Type 1 Diabetes is an autoimmune condition, typically developing in childhood, where the immune system destroys pancreatic beta cells, leading to absolute insulin deficiency.

Patients require lifelong insulin injections. Type 2 Diabetes, more common in adults, involves insulin resistance (cells don't respond to insulin) and/or insufficient insulin production, strongly linked to obesity and physical inactivity.

Management includes lifestyle changes, oral medications, and sometimes insulin.

Allergies are hypersensitivity reactions to innocuous substances (allergens). Upon first exposure, IgE antibodies are produced and bind to mast cells. Subsequent exposure triggers mast cells to release histamine and other inflammatory mediators, causing symptoms like sneezing, itching, and swelling. Asthma is a chronic inflammatory disease of the airways, leading to recurrent episodes of wheezing and breathlessness, often triggered by allergens or irritants.

Autoimmune diseases involve the immune system mistakenly attacking the body's own healthy tissues. Examples include Rheumatoid Arthritis (joints), Type 1 Diabetes (pancreatic beta cells), and Multiple Sclerosis (nervous system).

Deficiency diseases arise from a lack of essential nutrients. For instance, Vitamin C deficiency causes Scurvy (bleeding gums, fatigue), Vitamin D deficiency causes Rickets (bone deformities), Vitamin B1 (Thiamine) deficiency causes Beriberi (neurological and cardiovascular issues), and Iron deficiency causes Anemia (fatigue, weakness).

Prevention of NCDs heavily relies on healthy lifestyle choices (balanced diet, regular exercise, no smoking/excessive alcohol), minimizing environmental exposures, and early detection through screening programs.

Prelims Revision Notes

Non-Infectious Diseases (NCDs) - NEET Revision

1. Definition & Characteristics:

Not caused by pathogens (bacteria, viruses, fungi, parasites).
Not transmissible from person to person.
Often chronic, slow progression.
Multifactorial etiology: genetics, lifestyle, environment, age.

2. Major Categories & Examples:

Cancer: — Uncontrolled cell growth.

* Carcinogens: Agents causing cancer. * Physical: UV radiation (skin cancer), X-rays, gamma rays. * Chemical: Tobacco smoke (benzopyrene), asbestos, certain dyes. * Biological: Oncogenic viruses (HPV $\rightarrow$ cervical cancer, Hepatitis B/C $\rightarrow$ liver cancer). * Metastasis: Spread of cancer cells to distant sites. * Treatment: Surgery, Radiotherapy, Chemotherapy, Immunotherapy.

Diabetes Mellitus: — Disorder of glucose metabolism.

* Type 1 (Insulin-Dependent): Autoimmune destruction of pancreatic $\beta$-cells $\rightarrow$ absolute insulin deficiency. Requires exogenous insulin. * Type 2 (Non-Insulin-Dependent): Insulin resistance and/or relative insulin deficiency. Strong link to obesity, inactivity. Managed with lifestyle, oral drugs, sometimes insulin. * Symptoms: Polyuria (frequent urination), Polydipsia (excessive thirst), Polyphagia (excessive hunger).

Allergies: — Exaggerated immune response to harmless substances (allergens).

* Allergens: Pollen, dust mites, animal dander, certain foods, drugs. * Mechanism: IgE antibodies bind to mast cells $\rightarrow$ re-exposure $\rightarrow$ mast cell degranulation $\rightarrow$ release of histamine, serotonin $\rightarrow$ inflammation, symptoms. * Symptoms: Sneezing, watery eyes, runny nose, skin rashes, anaphylaxis (severe).

Asthma: — Chronic inflammatory disorder of airways.

* Triggers: Allergens, cold air, exercise, pollution, smoke. * Symptoms: Wheezing, shortness of breath, chest tightness, coughing.

Autoimmune Diseases: — Immune system attacks body's own tissues.

* Examples: Rheumatoid Arthritis (joints), Type 1 Diabetes, Multiple Sclerosis.

Deficiency Diseases: — Due to lack of essential nutrients.

* Vitamin A: Night blindness, xerophthalmia. * Vitamin B1 (Thiamine): Beriberi. * Vitamin B3 (Niacin): Pellagra (Dermatitis, Diarrhea, Dementia). * Vitamin C (Ascorbic Acid): Scurvy (bleeding gums, poor wound healing). * Vitamin D: Rickets (children), Osteomalacia (adults) $\rightarrow$ bone deformities. * Iron: Anemia (fatigue, pallor). * Iodine: Goiter (enlarged thyroid), cretinism (children).

3. Prevention:

Healthy lifestyle: balanced diet, regular exercise, healthy weight.
Avoid tobacco and excessive alcohol.
Minimize exposure to environmental pollutants and carcinogens.
Early detection and screening programs.

Vyyuha Quick Recall

To remember key Non-Infectious Diseases, think 'C.A.N.D.Y. A.S.S.':

Cancer
Allergies
Nutritional Deficiencies
Diabetes
Y — (hYpertension/cardiovascular diseases)
Asthma
Stroke (part of CVD)
Self-attacking (Autoimmune diseases)