Non-Communicable disease | MBBS community Medicine notes | Park community medicine notes| PSM notes | MBBS | WHO

 Non-Communicable Diseases (NCD’s)

Group of chronic diseases, where the causative agents are not clearly identified, but a set of risk factor have been identified to be associated.

📌Common NCD’s are: -

1. Cardiovascular diseases (IHD & CHD, RHD & RF)
2. Cerebrovascular Diseases (TIA & Stroke)
3. Hypertension
4. Diabetes Mellitus
5. Cancer
6. Obesity, 
7. Accidents

📌Characteristics of NCD’s

• Permanent
• Leave residual disability
• Non-reversible pathological alteration
• Require special training of the patient for rehabilitation
• Require long period of supervision, observation or care

📌Risk Factors of NCDs: -

Non- modifiable: -

1. Age
2. Sex
3. Genetic Disorder
4. Family history

Modifiable: -

1. Obesity
2. Salt intake
3. Saturated fat intake
4. Smoking
5. Less physical Activity
6. Stress
7. OCP 

🔍Prevention of NCD’s: -

Primary Prevention

1. Population Strategy

• Prevention in whole population
• Primordial Prevention in whole population

2. High Risk Strategy

Secondary Prevention

Tertiary Prevention

🔍NCD’s are increasing in population – Why?

📌Rapid change of: -

1. Food habit
2. Lifestyle and
3. Behavioral pattern of the people. 

Increasing proportion of adults and elderly population due to: -

1. Improved health status and converge
2. Economic development
3. Better education

🔍Impact of NCD’s

• Disability
• Loss of life
• Family hardship
• Poverty
• Economic loss of country

🔍Gaps in natural history of NCD’s

• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset

            HYPERTENSION           

📌Causes of Hypertension

Primary Hypertension Cause: Idiopathic (>90%)

Secondary hypertension Causes: (<10%)

• Alcohol
• Obesity
• Pregnancy
• Renal diseases
• Endocrine disease
• Drugs
• Coarctation of aorta

🔍Risk Factors of Hypertension: -   

Non- modifiable: -

1. Age
2. Genetic Factor
3. Family History

Modifiable: -

1. Obesity
2. Salt intake 
3. Saturated fat Intake
4. Alcohol intake
5. Smoking
6. Less Physical Activity
7. Stress
8. OCP
9. Noise, Vibration, Temperature

❓Rule of halves in Hypertension

Hypertension is an 'iceberg' disease. Only about half of the people in the general population of most developed countries are hypertensive. Half of them are aware of the condition, half of them are being treated, and only about half of those treated were considered adequately treated. It is known as "Rules of halves".

Rule of Halves

Rule of Halves

🔍Complications of Hypertension

1. Left ventricular hypertrophy (LVH)
2. Coronary artery disease (CHD)
3. Congestive cardiac failure (CCF)
4. Stroke
5. Renal failure
6. Peripheral vascular disease
7. Retinopathy
8. Encephalopathy

🔍Prevention of Hypertension

Primordial Prevention (Preventing emergence of risk factors in the community) (Promote healthy lifestyle from childhood. Avoid development of obesity, sedentary habits, high salt/fat diet.

✅Policies for:

1. Reducing salt in processed foods.
2. Regulating tobacco & alcohol.
3. Creating environments for physical activity (walkways, playgrounds).
4. School & community health education programs.

✅Prevention of Hypertension: -

🔍Primary Prevention (Preventing occurrence of hypertension in individuals at risk)

• Lifestyle modifications
• Reduce salt intake (<5 g/day).
• Maintain healthy body weight (BMI <25).
• Regular physical activity (≥150 min/week moderate activity).
• Diet: rich in fruits, vegetables, low in saturated fats
• Limit alcohol consumption.
• Avoid tobacco.
• Stress management (yoga, meditation, relaxation techniques).

🔍Secondary Prevention (Early detection & control of hypertension to prevent complications)

• Screening programs: opportunistic screening in all adults ≥18 years.
• Regular BP monitoring at community/primary health centers.
• Early initiation of lifestyle modification and drug therapy where indicated.
• Patient education on compliance with treatment.

🔍Tertiary Prevention (Prevent complications & disability in hypertensive patients)

• Strict BP control with drugs + lifestyle measures.
• Prevent and manage complications: stroke, heart failure, kidney disease.
• Rehabilitation services for those with established complications (physiotherapy, occupational therapy, counseling).

    Stroke    

Definition:

Stroke is a rapidly developing clinical syndrome of focal (or global) disturbance of cerebral function lasting >24 hours or leading to death, with no apparent cause other than vascular origin (WHO).

Public health importance:

• 2nd leading cause of death worldwide.
• Major cause of disability.
• Rising burden in low- and middle-income countries.

Epidemiology

• Global: ~15 million strokes/year; 5 million deaths; 5 million permanently disabled. 
• India & Bangladesh.
• Prevalence: 1.5–2/1000 population (increasing trend).
• Stroke belt: South Asia + Eastern India.

🔍Risk factors distribution (modifiable vs non-modifiable).

Non-modifiable

• Age (risk ↑ with age).
• Sex (slightly higher in males).
• Family history/genetic predisposition.

Modifiable

Major: Hypertension, diabetes, dyslipidemia, smoking, obesity, atrial fibrillation.

Lifestyle: High salt/fat diet, physical inactivity, excessive alcohol, stress.

Others: Infections, oral contraceptives (rare).

🔍Classification of Stroke

1. Ischemic stroke (≈80–85%): thrombosis, embolism, systemic hypoperfusion.
2. Hemorrhagic stroke (≈15–20%): intracerebral hemorrhage, subarachnoid hemorrhage.
3. Transient Ischemic Attack (TIA): symptoms resolve <24 hours.

Clinical Features 

• Sudden onset of: Weakness/numbness of face/arm/leg (especially unilateral).
• Speech disturbance.
• Loss of vision, balance, coordination.
• “FAST” symptoms: Face drooping, Arm weakness, Speech difficulty, Time to act fast.

🔍Prevention & Control

a. Primordial Prevention: - 

• Promote healthy lifestyle from childhood.
• Salt reduction, anti-tobacco/alcohol campaigns.
• Policy measures for healthy diet & physical activity.

b. Primary Prevention: -

• Control of hypertension (most important).
• Diabetes & dyslipidemia management.
• Promote physical activity.
• Reduce obesity, avoid tobacco, alcohol moderation.
• Screening & prophylaxis for atrial fibrillation (anticoagulants).

c. Secondary Prevention: -

Early detection: Screening for high BP, diabetes, atrial fibrillation.

Prompt treatment: Rapid referral for suspected stroke (golden window for thrombolysis <4.5 hrs). Antiplatelets/anticoagulants, BP control.

d. Tertiary Prevention: -

Rehabilitation: physiotherapy, speech therapy, occupational therapy. Prevent recurrence with lifestyle modification + medicines. Social & vocational rehabilitation for disabled patients.

Rheumatic Fever (RF) / Rheumatic Heart Disease (RHD)

Rheumatic fever is a febrile disease affecting connective tissue particularly heart and joints initiated by infection of throat by group-A beta hemolytic streptococci. Although RF is not a communicable disease, it results from a communicable disease (Streptococcal Pharyngitis) RF often leads to RHD which is crippling disease

The consequences of RHD include:

• Continuing damage to the heart
• Increasing disabilities
• Repeated hospitalization
• Premature death (35 years or even earlier)

Note: - RHD is one of the most readily preventable chronic disease

🔍Epidemiological Triad

Agent: - Group A β-hemolytic Streptococcus (Streptococcus pyogenes)

Host: - 

• Children 5–15 years 
• Genetic susceptibility
• Previous RF attack

Environment: -

• Overcrowding
• Poverty
• Poor housing
• Limited access to healthcare

🔍Epidemiological features of RF

Socioeconomic status: RF is a social disease linked to poverty, overcrowding, poor housing and inadequate health services.

High risk groups: The school-age children between 5 and 15 years, slum dwellers and those living in a closed community (e.g. barracks)

📌Modified 2015 Jones Criteria:

Major Criteria – Five (5)

1. Carditis
2. Migratory Polyarthritis
3. Sydenham’s Chorea
4. Subcutaneous Nodule
5. Erythema Marginatum

Minor Criteria

1. Polyarthralgia
2. Hyperpyrexia
3. ESR >= 60mm/h and or CRP >=3 mg/dl
4. Prolonged PR interval

🔍Prevention: -

According to Park, RF/RHD prevention is discussed under the levels of prevention framework.

1) Primordial Prevention: - 

• Prevent emergence of risk factors.
• Poverty reduction
• Better housing
• Reduced overcrowding
• Improved sanitation
• Improved access to healthcare
• Primary Prevention

2) Prevent first attack of RF.

• Early diagnosis of streptococcal sore throat
• Adequate penicillin treatment
• Health education regarding early treatment seeking

3) Secondary Prevention: -

• Prevent recurrence of RF and progression to RHD.
• Most effective strategy
• Long-term Benzathine Penicillin prophylaxis
• Regular follow-up of RF/RHD patients
• Patient registry and surveillance

4) Tertiary Prevention: -

• Reduce complications and disability.
• Heart failure management
• Anticoagulation when indicated
• Valve repair/replacement

5) Rehabilitation 

     Diabetes Mellitus     

Diabetes Mellitus (DM) is a group of metabolic disorders characterized by chronic hyperglycaemia resulting from defects in insulin secretion, insulin action, or both. Additionally, disturbance in metabolism of protein, fat and CHO

🔍Public Health Importance

One of the major Non-Communicable Diseases (NCDs) globally. Causes significant morbidity and mortality.

🔍Major contributor to:

• Cardiovascular diseases
• Chronic kidney diseas.
• Blindness
• Lower limb amputations
• Leads to substantial economic burden on families and health systems.

📌Classification: -

Type 1 Diabetes: -

• Autoimmune destruction of β-cells
• Absolute insulin deficiency
• Usually occurs in childhood and adolescence

Type 2 Diabetes: -

• Insulin resistance with relative insulin deficiency
• Accounts for about 90–95% of all diabetes cases
• Strongly associated with obesity and sedentary lifestyle

Other Specific Types: -

• Genetic defects
• Pancreatic diseases
• Drug-induced diabetes

Gestational Diabetes Mellitus (GDM): -

Diabetes first detected during pregnancy

🔍Risk Factors: -

Non-modifiable Factors: -

• Increasing age
• Family history
• Ethnicity
• History of gestational diabetes

Modifiable Factors: -

• Overweight and obesity
• Physical inactivity & Unhealthy diet
• Tobacco use & Excess alcohol consumption
• Hypertension
• Dyslipidemia

🔍Clinical Features: -

Classic Symptoms

• Polyuria
• Polydipsia
• Polyphagia
• Weight loss

Other Features

• Fatigue
• Recurrent infections
• Delayed wound healing
• Blurred vision

🔍Screening: -

• High-Risk Groups
• Age ≥40 years
• Obesity
• Family history of diabetes
• Hypertension
• Previous gestational diabetes
• Sedentary lifestyle

Screening Methods

• Fasting blood glucose
• Oral glucose tolerance test (OGTT)
• HbA1c

🔍Diagnosis (WHO Criteria): -

Test with value

Fasting Plasma Glucose: - ≥ 126mg/ dl (7.0mmol/L)

2 Hour Plasma Glucose (OGTT): -≥200mg/dl (11.1 mmol/L)

Random Plasma Glucose + Symptoms ≥200mg/dl

HbA1c ≥6.5%

📌Complications

Acute: - 

• Diabetic ketoacidosis (DKA)
• Hyperosmolar hyperglycemic state (HHS)
• Hypoglycemia

Chronic: -

• Microvascular
• Retinopathy
• Nephropathy
• Neuropathy
• Macrovascular
• Coronary artery disease
• Stroke
• Peripheral vascular disease

🔍Prevention of Diabetes: -

Primordial Prevention: -

Prevent development of risk factors:

• Healthy lifestyle from childhood
• Healthy diet
• Regular physical activity
• Avoidance of obesity and tobacco use

Primary Prevention: -

• Weight control
• Physical activity (≥150 minutes/week)
• Balanced diet rich in fruits and vegetables
• Reduction of sugar and saturated fat intake
• Prevention of Diabetes

Secondary Prevention: -

• Early detection through screening of Screening of high-risk individuals
• Early diagnosis and treatment

Tertiary Prevention: -

Prevent complications by 

• Glycemic control
• Foot care
• Eye examination
• Management of hypertension and dyslipidemia

     Obesity    

Obesity is one of the most important NCD risk factors worldwide. It results from excessive accumulation of body fat to an extent that may impair health and increase the risk of morbidity and mortality. It has become a major public health problem due to rapid urbanization, sedentary lifestyles, and unhealthy dietary practices.

Overweight: Excess body weight relative to height.

📌Waist Circumference

High risk when: -

• Men: >90 cm (Asian population)
• Women: >80 cm (Asian population)

🔍Importance: -

Central obesity is more strongly associated with:

• Type 2 diabetes
• Hypertension
• Cardiovascular disease
• Metabolic syndrome

🔍Risk Factors: -

Non-Modifiable Factors: -

• Age
• Genetic predisposition
• Family history
• Sex

Modifiable Factors: -
Dietary Factors

• Excess calorie intake
• Fast foods
• Sugary beverages
• High-fat diets

Physical Inactivity

• Sedentary lifestyle
• Lack of exercise

Behavioral Factors

• Stress
• Sleep deprivation
• Excessive screen time

Environmental Factors: - 

• Urbanization, 
• Easy availability of processed foods,

📌Health Consequences

Metabolic Disorders

• Type 2 diabetes mellitus
• Dyslipidemia
• Metabolic syndrome

Cardiovascular Diseases

• Hypertension
• Coronary artery disease
• Stroke

Musculoskeletal Disorders

• Osteoarthritis
• Back pain
• Respiratory Disorders
• Obstructive sleep apnea

📌Cancers

Increased risk of: -

• Breast cancer
• Endometrial cancer
• Colorectal cancer

🔍Prevention of Obesity: -

Primordial Prevention: -

• Prevent emergence of risk factors:
• Healthy eating habits from childhood
• School health education for Promotion of active lifestyles
• Prevention of sedentary behavior
• Prevention of Obesity

Primary Prevention: -

Prevent occurrence of obesity: 

Healthy Diet

• Increase fruits and vegetables
• Reduce saturated fats ultra-processed foods
• Limit sugar and salt intake

Physical Activity

• At least 150 minutes/week of moderate activity
• Regular exercise

Lifestyle Modification

• Weight monitoring
• Adequate sleep and Stress management

Secondary Prevention: -

Early detection and intervention:

• BMI screening
• Waist circumference measurement
• Identification of high-risk individuals
• Lifestyle counseling

Tertiary Prevention: -

Prevent complications: 

• Weight reduction programs
• Management of diabetes and hypertension
• Dietary therapy and Physical activity programs
• Long-term follow-up

      Cancer     

Cancer is a group of diseases characterized by uncontrolled and abnormal proliferation of cells with the ability to invade surrounding tissues, metastasize to distant sites, and the eventual death of the affected patient if the tumor has progressed beyond that stage when it can be successfully removed.

It can occur any site or tissue of the body and may involve any types of cell.

🔍Epidemiological Importance: -

• Cancer is one of the leading causes of morbidity and mortality worldwide.
• It is a major component of the growing burden of Non-Communicable Diseases (NCDs).
• Incidence increases with age.
• Many cancers are preventable through modification of risk factors.

📌Major Risk Factors

• Tobacco (Most Important Preventable Cause)- Lung, Oral, Laryngeal cancer, Esophageal cancer, Bladder cancer
• Dietary Factors- High-fat diet, Low fruit and vegetable intake, Obesity
• Alcohol Consumption-Oral, Esophageal and Liver cancer Infections-HPV → Cervical cancer, HBV/HCV → Liver cancer, H. pylori → Gastric cancer, EBV → Certain lymphomas
• Environmental & Occupational Factors- Radiation (UV, ionizing radiation), Asbestos, Benzene, Arsenic
• Genetic Factors- Family history, Inherited mutations

📌Type of cancer in MALE: -

1. Bronchogenic Carcinoma 
2. Ca Stomach
3. Colorectal Cancer
4. Oropharyngeal Carcinoma
5. Lymphoma 
6. Skin Cancer

📌Type of cancer in FEMALE: -

1. Ca Breast
2. Ca Cervix
3. Ovarian Carcinoma
4. Bronchogenic Carcinoma
5. Ca Stomach
6. Colon Cancer

🔍Prevention: -

📌Primordial Prevention (emergence of risk factor)

• Promote healthy lifestyle from childhood.
• Tobacco-free environment.
• Healthy dietary habits.
• Regular physical activity.
• Health education in schools and communities.
• Environmental protection against carcinogenic exposures.

📌Primary Prevention (Prevent occurrence of cancer by controlling risk factors)

• Health Promotion
• Avoid tobacco in all forms.
• Limit alcohol consumption.
• Consume a balanced diet rich in fruits and vegetables.
• Maintain healthy body weight.
• Engage in regular physical activity.
• Practice safe sexual behavior.

📌Specific Protection: -

• HPV vaccination (Cervical cancer)
• Hepatitis B vaccination (HCC)
• Protection from ultraviolet radiation.
• Occupational safety measures (asbestos, benzene, radiation etc.)
• Reduce pollution.

📌Secondary Prevention: -

Objective: Early detection and prompt treatment of precancerous lesions and early-stage cancers.

📌Tertiary Prevention: -

Objective: Reduce disability, complications, recurrence, and improve quality of life.
Measures: 

• Early and adequate treatment (surgery, chemotherapy, radiotherapy).
• Rehabilitation services.
• Psychological counseling.
• Palliative care.
• Pain management.
• Follow-up for recurrence and metastasis.

🔍Cancer Screening: -

It is the presumptive identification of unrecognized cancer or precancerous lesions by applying tests, examinations, or procedures to apparently healthy individuals, so that those who are likely to have the disease can be investigated further and treated early.

Objectives of Cancer Screening: -

• Detect cancer at an early stage.
• Detect precancerous lesions before malignant transformation.
• Reduce cancer-related morbidity and mortality.
• Improve survival and quality of life.

     Arsenicosis    

Arsenicosis is a chronic health condition caused by prolonged ingestion of arsenic-contaminated water or food, resulting in characteristic skin lesions and systemic toxic effects.

Public Health Importance

1. It is a major environmental health problem.
2. Affect Countries such as Bangladesh and parts of India.
3. Exposure usually occurs through drinking contaminated tube-well water.
4. Considered one of the largest mass poisonings in the world.

Sources of Arsenic Exposure

• Natural Sources
• Arsenic-containing rocks and sediments.
• Groundwater contamination due to geological processes.
• Anthropogenic Sources 
• Mining and smelting industries.
• Pesticides and herbicides.
• Industrial waste.

Main Route of Exposure

• Drinking arsenic-contaminated groundwater.

🔍Safe Limit

WHO Guideline Value: 10 µg/L (0.01 mg/L)

Bangladesh Standard: 50 µg/L (0.05 mg/L)

Long-term consumption above these levels increases health risks.

🔍Clinical Features: -

Early Symptoms- Weakness, Fatigue, Loss of appetite, Nausea, Abdominal discomfort

Skin Manifestations- 

• Melanosis- Raindrop” appearance on trunk and limbs.
• Keratosis (Melanosis and keratosis are hallmark signs of chronic arsenicosis)

Systemic Manifestations- Neurological, Cardiovascular, Respiratory, Gastrointestinal, Hepatic

🔍Prevention and Control: -

📌Primary Prevention

• Safe Water Supply
• Use arsenic-free tube wells.
• Deep tube wells where appropriate.
• Surface water treatment.
• Rainwater harvesting.
• Water Testing
• Regular testing of drinking water sources.
• Marking safe and unsafe wells.
• Health Education
• Community awareness regarding arsenic hazards.
• Promotion of safe water use.

📌Secondary Prevention

• Early detection of skin lesions.
• Screening in endemic communities.
• Prompt referral and treatment.

📌Tertiary Prevention

• Management of complications.
• Rehabilitation.
• Cancer surveillance.

Accidents

An unintended and unpremeditated event Results are unexpected injury, death or property damage.

Types of accidents 

1. Road Traffic Accidents (RTA)
2. Industrial Accidents
3. Household Accidents
4. Sports Accidents
5. Accident in Public Places

Prevention of Accidents

Accident research – Data collection, analysis and interpretation.

Community Education about – Safety, Vehicle rules, Traffic rules.

Intervention of four (4) ‘E”: -

1. Engineering Intervention
2. Economic Intervention
3. Enforcement (Law & Regulation) Intervention
4. Educational Intervention

🔍Epidemiology of RTA: -

Agent Factors:

• Mechanical or Kinetic energy
• Host Factors:
• Alcohol or Drug Abuse, Use of Stolen Vehicle
• Poor Vision, Lack of protective equipment (Seat belts)

Environment Factors:

Defective Road Design, Faulty Road Barrier, Faulty Speed Backers, Mix Fast & slow Traffic, Inadequate Law Enforcement, Over loading, Bad Weather.

🔍Prevention of RTA

a. Primordial Prevention (Prevent development of risk factors)

• Urban planning to reduce traffic congestion.
• Policies for safe transport system development with strict licensing systems (driver fitness, age limit).
• Legislation on vehicle safety standards.

b. Primary Prevention (Prevent occurrence of accidents)

Host factors (Human behavior)

• Health education on safe driving.
• Avoid alcohol, drugs, mobile phone use while driving.
• Adequate rest for drivers (avoid fatigue).
• Use of seat belts, helmets, child restraints.
• Vision and hearing screening for drivers.

Agent factors (Vehicle safety)

• Regular vehicle maintenance.
• Installation of safety devices: airbags, anti-lock braking system, indicators.

Environmental factors (Road & traffic system)

• Well-designed roads with dividers, speed breakers, pedestrian crossings, proper lighting.
• Traffic signs, road markings, speed limits.
• Separate lanes for heavy vehicles, bicycles, pedestrians.
• Improved public transport systems.

C. Secondary Prevention (Reduce severity after accident occurs)

• Rapid emergency services (ambulance, paramedics).
• First aid training for public and drivers.
• Trauma care centers along highways.
• Effective referral system to hospitals.

D. Tertiary Prevention (Reduce disability & restore function)

• Comprehensive rehabilitation (medical, physical, psychological, vocational).
• Social security & insurance support for victims and families.
• Enforcement of disability rights.

Thank you........& Best of luck...........

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