Why do we get swelling?

Hint: Swelling occurs whenever the organs, skin or other parts of our body enlarge. Swelling can have causes that are not due to underlying disease. It is typically the result of inflammation or a build up of fluid.

Complete answer:
It is the result of the increased movement of fluid and white blood cells into the injured area.

It is a symptom of a variety of conditions but there is always an underlying cause. Sometimes the source of swelling can be serious and requires immediate medical attention.

Body parts swell when body fluid is retained in a certain tissue, joint,etc.
It can be internal, external, localised or generalized.
External swelling- Affecting skin, muscle and is caused by an insect bite, illness or injury. Internal swelling affects the internal organs of the body and usually has a more serious cause.
Localised swelling- Is confined to just one area of the body, such as from a bee sting or an ankle sprain. It affects the whole body and is often the result of a major traumatic injury.

Reason for swelling:
Injuries include strikes to the body, sprain, muscle strain, bone fracture, etc because small tears in the surrounding blood vessels cause fluid to leak into the area.
Infection- Some other fluid from at the site of infection. This indicates the presence of infection-fighting white blood cells.
Allergic reaction- Large areas of the body may swell, like swelling of the face, tongue or throat.
Inflammation- Joints or tendons may swell after repeated overuse.
Pregnancy- Swelling of the hand and feet occurs.

Note:
We can reduce swelling by taking plenty of rest to protect our affected areas, taking doctors help for treating the affected area. Some medications and exercise are the most effective methods to reduce it.