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Introduction to Diseases

When the normal human body condition deteriorates, then the condition is known as disease. Each disease has its own signs and symptoms. It can also be defined as a divergence of human body condition from its normal state. Example: when a person comes in contact with any kind of harmful pathogen, then in that case they show certain symptoms depending on body condition, which may be called a disease. Hence, in order to know about which kind of disease we are suffering through, we have to study all types of diseases. It's not necessary that a disease will show only a single symptom as it can show many symptoms also depending upon variation of the disease. Some of the very common symptoms of diseases are headaches, cough, cold, weakness. 

Types of Diseases:

Diseases are categorised into two types, they are:

A. Infectious Disease: 

It is a kind of disease that can be transmitted from one person to another, and due to this reason they are called communicable diseases. Such diseases are mainly caused by microorganisms, which are termed as pathogens like: (fungi, rickettsia, bacteria, viruses, protozoans, worms). When a fluid of an infected person is discharged then at that time pathogens may leave the host and infect a new person's body. Body fluid is discharged by processes like sneezing, coughing etc. Examples of infectious disease are Cholera, chickenpox, malaria etc.

B. Non-infectious Disease: 

In this type of disease, people get infected by pathogens, but along with that other factors also play a role: age, nutritional deficiency, the gender of an individual, and lifestyle also influence the disease. Examples of non-infectious diseases are hypertension, diabetes, and cancer. As this disease cannot be transferred from one person to another so it remains inside the single person only. 

Classification of Diseases on the Basis of Duration:

Based on duration, diseases can be categorised into two types:

A. Acute Disease:  It is a kind of disease which occurs only for a short interval of time. An acute disease, if not treated properly, can eventually become a chronic disease. e.g. common cold, burn, etc.

B. Chronic Disease: It is a kind of disease which lasts for a long duration of time. Some of the common examples of this disease are heart and kidney diseases.


It is a kind of bacterial disease which is mainly caused by the bacterium Vibrio cholerae. We can get this bacteria mainly in contaminated foods and water. It is also present in areas where there are no proper sanitation facilities. Discovery of this disease took place in the US during the 1800s and it caused major health problems to people for hundreds of years. Some of the commonly known symptoms of this disease are severe diarrhoea and leading to dehydration in the body and sometimes it might lead to a fatal condition.

About Cholera Bacteria:

The scientific name of cholera bacteria is Vibrio cholerae, it is mainly curved and comma-shaped and is gram-negative bacteria. It is mostly found in coastal saltwater areas and in the sewage. They attach themselves to the shells of shell-fish, crabs, etc. When we drink contaminated water it causes various threatening diseases and one among them is cholera.

They live in the small intestine of the human body and release an exotoxin that causes a flow of water and certain electrolytes such as the sodium bicarbonate, chloride etc, into the small intestine.

Symptoms of Cholera:

Some of the common symptoms of cholera are discussed below:

A. High fever.

B. Lead to increased thirst.

C. Sudden weight loss.

D. Decrease in blood pressure.

E. Feeling of Nausea

F. Formation of blood or mucus or sometimes undigested materials in the stool.

G. A kind bloating in the belly.

H. decrease in elasticity of the skin.

I. Causes cramps in the muscles.

J. Dryness in the mouth, nose, and eyelids.

K. Vomiting sensation

L. A sudden increase in the heart rate.

Causes of Cholera:

Some of the common causes of cholera are discussed below: 

A. It can be caused by various factors like contaminated water supply or by drinking contaminated water. 

B. It can also be caused by consumption of contaminated foods and drinks like street food. 

C. Vegetables can also cause cholera-like the vegetables which are grown with the use of water with human wastes.

D. By eating contaminated sea-foods, which are polluted with sewage.

E. It can also be caused by the consumption of foods that affect the functioning of the digestive system.

Preventative Measures:

Some of the precautions which we can take to protect us from cholera are discussed below:

A. By drinking boiled water.

B. By avoiding consumption of raw foods.

C. By avoiding dairy products as much as you can.

D. By washing fruits and vegetables before you eat or use them for cooking purposes.

E. Washing your hands properly before you eat is the easiest way to protect yourself from the disease.

F. Drink plenty of water and it is recommended to drink about 8 ounces of water every day.

FAQ (Frequently Asked Questions)

1. How Cholera Can be Treated?

Ans. Cholera can be treated by the replacement of lost fluid and electrolytes. Also, the drinking of plenty of ORS (Oral rehydration solution) is suggested to prevent dehydration inside your body. In case condition worsens, intravenous fluid replacement may be required. Apart from that doctors also suggest antibiotics and Zinc supplements, to check diarrhoea.

2. Explain the Term Non-Communicable Disease?

Ans. In this type of disease, factors such as nutritional deficiency, age, the gender of an individual, and lifestyle influence the disease although the individual may be affected by a pathogen(s). Examples of non-infectious diseases include hypertension, diabetes, and cancer. These diseases cannot be transferred from one person to another and thus, remain inside the one person only.