In less common cases, unexplained bruising may be related to problems such as anemia, thrombocytopenia (low platelet count), or clotting disorders.

When to See a Doctor

You should seek medical attention if:

Bruises appear frequently for no clear reason.

They are large, painful, or change color very slowly.

They appear on several parts of the body at the same time.

They are accompanied by bleeding from the gums, nose, or heavy menstruation.

You have a family history of blood disorders.

Recommendations

Change your sleeping position to avoid pressure on your arms.

Use comfortable bedding that doesn’t constrict or cause friction.

Increase your consumption of fruits and vegetables rich in vitamins C and K.

Avoid self-medicating with blood thinners or supplements without medical advice.

Maintain good hydration and exercise moderately to improve circulation.

Conclusion

Bruises on the arms while sleeping are common and, in most cases, harmless. They are usually due to posture, pressure on the body, or capillary fragility. However, if they occur frequently or without an apparent cause, it is best to consult a health professional to rule out underlying conditions.