What causes sudden black or purple discoloration of the palm?

Generally, sudden black or purple discoloration of the palm may be caused by cold stimulation, external pressure, Raynaud's syndrome, thromboangiitis obliterans, or pulmonary heart disease. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under a doctor's guidance. Specific analyses are as follows:

1. Cold stimulation: Low temperatures cause constriction of blood vessels in the palm, slowing blood flow and leading to blood stagnation and discoloration. Immediately move to a warm environment, soak hands in warm water to promote circulation, and wear thick gloves for protection when going outdoors.

2. External pressure: Prolonged compression or trauma to the palm can rupture local blood vessels, causing bruising and discoloration. If the skin is unbroken, apply cold compresses within the first 48 hours to reduce bleeding, then switch to warm compresses after 48 hours to facilitate absorption of the hematoma, and avoid re-compression.

3. Raynaud's syndrome: When exposed to cold or emotional stress, small arteries in the palm spasm and constrict, interrupting blood flow and causing color changes along with numbness and tingling. Patients may take medications such as nifedipine sustained-release tablets, tolazoline hydrochloride tablets, or nicotinic acid tablets as prescribed to relieve vascular spasms.

4. Thromboangiitis obliterans: Vascular inflammation leads to thrombosis, resulting in insufficient blood supply to the palm, causing black or purple discoloration accompanied by intermittent claudication. Patients should take medications such as enteric-coated aspirin tablets, clopidogrel hydrogen sulfate tablets, or alprostadil injection as directed. In severe cases, thrombectomy may be performed to restore blood flow.

5. Pulmonary heart disease: Abnormal heart and lung function causes systemic hypoxia and reduced blood oxygen levels, leading to cyanosis and darkening of the palms, often accompanied by difficulty breathing. Patients may use medications such as aminophylline tablets, budesonide/formoterol powder for inhalation, or furosemide tablets as prescribed to improve cardiopulmonary function.

In daily life, avoid prolonged exposure of the hands to cold environments and maintain emotional stability to reduce vascular irritation. Perform appropriate hand stretching exercises to promote peripheral circulation. Maintain a light, low-salt diet to avoid increasing the burden on the heart and lungs.