After swimming, there are blue and purple patches on the body.

Generally, bruising or purplish discoloration on the body after swimming may be caused by factors such as lack of physical exercise, accidental collisions, water pressure, abnormal blood clotting function, or loss of vascular elasticity. Patients are advised to follow medical advice for symptomatic treatment. Specific analyses are as follows:

1. Lack of Physical Exercise

If a person normally lacks physical activity and suddenly engages in intense exercise, it may lead to muscle or blood vessel damage, resulting in bruising after exercise. Within the first 24 hours, cold compresses can be applied to help reduce swelling and pain. After 24 hours, local heat application may improve blood circulation and help resolve the bruising.

2. Accidental Collision

During exercise, accidental impact to the skin may cause localized subcutaneous bleeding, leading to bruising afterward. Usually, no special treatment is required, but proper skin care should be taken, and applying heat locally can aid in recovery.

3. Water Pressure Effects

While swimming, the body is subjected to water pressure, especially at greater depths. This pressure may cause skin bruising or discoloration. If chest tightness occurs due to water pressure, it is recommended to stop swimming immediately and rest to alleviate symptoms.

4. Abnormal Blood Clotting Function

Bruising after exercise is often due to impaired clotting function, which may affect local blood circulation and lead to bruising. Under a doctor's guidance, medications such as dexamethasone tablets or vitamin B1 tablets may be used for treatment.

5. Loss of Vascular Elasticity

With aging, sun exposure, hormonal changes, and other factors, the elasticity of skin and blood vessels gradually decreases. This may weaken the blood vessels' ability to constrict, significantly impairing the clotting mechanism and ultimately causing bruising. Medications such as aspirin tablets or warfarin sodium tablets may be used as directed by a physician.

If symptoms are severe, prompt medical attention is recommended to avoid delaying diagnosis and treatment. Maintaining healthy lifestyle habits in daily life contributes to overall well-being.