[Biology Class Notes] on Diseases- Types of Diseases and Their Symptoms Pdf

A Disease is a condition that is abnormal and negatively affects the structure and functioning of organs or tissues or parts of a living organism. It has to be noted that it is not due to any immediate external injury and disease is a medical condition that has specific signs and symptoms. 

Therefore, it can be stated that a disease is a discomfortable condition that deteriorates the normal functioning of the cells, organs, and tissues.

OR

Any risk caused due to divergence from the normal or functional state of an entity can be termed as a disease.

Any adverse variation from an organism’s normal structural or functional condition is usually associated with specific signs and symptoms and distinct from physical injury. A diseased organism will frequently display indications or symptoms that indicate its aberrant state. To recognize the symptoms of sickness, one must first understand the normal state of an organism. Nonetheless, there isn’t always a clear line between disease and wellness.

A few diseases appear out of nowhere and persist only a few days. Acute diseases, such as the common cold, are examples of them. Medical treatment or self-treatment are also options for treating this illness. Acute diseases frequently become chronic if they are not treated.

Acute illnesses can affect any part of the body. An asthma episode, for example, is acute and then becomes chronic. Acute diseases include strep throat, fractured bones, appendicitis, influenza, pneumonia, and others.

Acute diseases develop quickly and are accompanied by unique symptoms that necessitate immediate or short-term treatment and improve once treated. A fractured bone, for example, that may occur as a result of a fall, must be treated by a doctor and will recover over time. Acute illnesses, such as the common cold, can sometimes go away on their own. The majority of those who suffer from acute illnesses will recover quickly. If you’ve been hospitalized for an acute illness, you’ll probably be ready to get back to the comfort and familiarity of the home once your condition improves. However, just because you’ve been released from the hospital doesn’t imply you’ve entirely recovered. Find out what steps you may take to speed up your return to your regular routine.

Chronic diseases are illnesses that develop over time and endure for a long time or even a lifetime. Chronic disease is defined as a disease that lasts more than three years. The symptoms are relatively modest at first. The chronic disease develops slowly and causes significant damage to the body. It has the potential to be lethal at times.

Age, gender, and an unhealthy lifestyle, among other things, are risk factors for such diseases. Medication may or may not be able to cure a chronic disease. Vaccines are also ineffective in preventing it. Chronic diseases include hypertension, arthritis, diabetes, and psoriasis.

Chronic illnesses take longer to develop can progress over time and can present with a variety of warning signs or none at all. Arthritis, Alzheimer’s disease, diabetes, heart disease, high blood pressure, and chronic kidney disease are all common chronic illnesses. Chronic illnesses, unlike acute illnesses, cannot be cured; they can only be managed. Living with chronic illness or managing the symptoms of a chronic condition can often be accomplished by working with your doctor to develop a health care plan that includes medication, healthy eating, physical or occupational therapy, exercise, and complementary treatments like acupuncture or meditation. Staying physically active, maintaining a healthy weight and nutritional status, minimizing sun exposure, and refraining from smoking are all examples of good lifestyle practices that can help prevent chronic diseases.

In order to decide the appropriate course of treatment, it is necessary to correctly identify the etiology of an illness.

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We have classified various types of diseases based on their nature and the parts of the body they affect in the below tabular form-

Types of Diseases

Different Types of Diseases and Their Causes

Two Classification of Diseases

• Infectious Diseases

• Non-infectious Diseases

1. Infectious Diseases

Diseases that can spread from one person to another are called communicable diseases and are caused by microorganisms. The microorganisms that usually cause infectious diseases are called pathogens  include viruses, bacteria, fungi, rickettsia, worms, and protozoans. It spreads when the infected person transmits his/her bodily fluids to another person, and the pathogens may exit the host to infect the new person, it takes place during sneezing, coughing, etc. Various examples of this kind of disease are cholera, chickenpox, malaria, COVID-19, etc.

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2. Non-Infectious Diseases

These kinds of diseases are caused due to pathogens as well as other factors that include age, gender of an individual, deficiency in nutrition, unhealthy lifestyle, etc. Some of the examples include hypertension, cancer, and diabetes. These are noncommunicable and do not spread from one person to another. These restrain within a person who contracts them. Some of the examples include cataracts, Alzheimer’s, cataracts, and heart diseases.

Depending on which Above Categories of Diseases it Falls into, Diseases can be further Classified as

Are caused due to the malfunctioning of vital body organs as a result of the deterioration of cells over time. One of the best examples is Osteoporosis which causes increased bone weakness with time and it increases the risk of bone fracturing. Another is a neurodegenerative disorder when degeneration happens to the cells of the CNS like neurons. In Alzheimer’s, it often happens due to aging and bodywear. Some of these diseases are hereditary and because of bad lifestyle choices.

When the body becomes hypersensitive to certain foreign substances namely allergens, allergic reactions take place. It occurs when the immune system reacts abnormally to any foreign substances which can be harmless. Common allergens are dust, pollen, mites,  animal dander, latex, feathers, and also certain food products like gluten and nuts. Many people face allergies from food substances such as peanuts or other nuts and induce life-threatening conditions. It aggravates difficulty in breathing, swelling of tissues, and blocking of airways.

Other common symptoms that are less life-threatening include coughing, running nose, sneezing, itchy and red eyes, skin rashes. Asthma is an example of an allergic disease, others include bee stings, ant bites, etc. 

Deficiency diseases are caused due to the deficiencies of hormones, vitamins, minerals, and nutrients in the body. For example, diabetes occurs due to an inability to produce or utilize insulin, goiter is caused due to iodine deficiency, kwashiorkor is caused due to deficiency of proteins in the diet. Vitamin B1 deficiency results in a disease called beriberi.

An abnormal enlargement of the thyroid gland that results with blockage of the oesophagus or other organs of the chest and neck is called Goitre. It causes difficulty in breathing and eating.

Blood disorders result due to the effects on the blood plasma, platelets, white blood cells, and red blood cells. For example, Sickle Cell Anaemia is a condition when the red blood cells are destroyed or distorted in the shape of a sickle. It loses the ability to carry oxygen. As a result, it shows symptoms the same as in chronic anemia that includes shortness of breath and tiredness.