The blackening of each joint of the fingertips may be caused by post-inflammatory hyperpigmentation, peripheral microcirculation disorders, diabetes and other reasons.
1. Post-inflammatory hyperpigmentation: If the joints of the hands have suffered from eczema, skin infections and other inflammatory reactions, the local inflammation will stimulate the melanocytes, secrete a large number of melanin particles and precipitate in the local area, resulting in the symptom of blackened fingertips in each joint.
2. Peripheral microcirculation disorders: If the body suffers from hypoxia, or cold stimulation, it will cause peripheral microcirculation disorders, which will lead to ischemia of the local finger joints and cause blackening symptoms.
3. Diabetes: If the patient has diabetes, it will lead to local microvascular lesions in the fingers, thus causing the symptom of blackening of each joint of the fingertips.
Each joint of the finger is black, there may be other reasons, should go to the hospital to improve the examination, clear cause, give targeted treatment.