Black spots on the hands: causes and next steps

Marks on the back of the hands often receive substantial sunlight, while spots on the palms, fingers or beneath a nail have a different range of explanations. Notice when the mark began, whether it follows trauma, and whether its colour, size or surface is changing.

Flat tan or dark areas on sun-exposed hand skin may be pigment spots. A stain from dye or metal sits on the surface, whereas pigment within the skin will not wash away. Inflammation from eczema, a bite, a small burn or a healed wound can also leave lingering colour.

A dark line or patch under a nail may follow an injury and move outward as the nail grows, but unexplained nail pigment requires assessment. Roughness, a lump, scale or recurrent crusting suggests that the issue involves skin texture as well as colour.

Apply broad-spectrum sunscreen to the backs of the hands and reapply after washing or prolonged outdoor exposure. Use gloves for cleaning chemicals and moisturise after frequent handwashing to reduce irritation. Do not cut, file, bleach or freeze a dark mark yourself.

Photograph the spot beside a ruler in consistent light so you can describe genuine change. If a clinician confirms benign pigment, treatment may include a topical product or a procedure selected for its depth and your skin tone; hands also need careful aftercare because they are washed and exposed frequently.

Get prompt medical review for rapid enlargement, irregular edges, several colours, spontaneous bleeding, an open sore, persistent pain or a mark that looks unlike your others. A new unexplained dark band under one nail, pigment spreading onto nearby skin, or nail distortion also warrants assessment.

Seek urgent help if dark colour appears with a severe crush injury, marked swelling, loss of sensation, a cold finger or worsening pain. These features concern circulation or tissue injury, not merely cosmetic pigmentation.

Ask whether the spot needs dermoscopic examination, whether its location under a nail changes the assessment, and if treatment could scar or alter pigment. Explain recent injuries, occupational exposures, hobbies involving dyes, and any family history of unusual moles or skin cancer.