How can you tell if you have skin cancer?

Skin cancer. The only way to know is to have a dermatologist evaluate any suspicious lesion. A skin biopsy will confirm whether it is cancerous or not.
Biopsy. The only way to tell if you have a skin cancer is by a biopsy. If you have a new or changing lesion that concerns you, seek the advice of a physician who can decide if a biopsy is needed.