How do i clear up black toe mail? all my other toe nails seem to clear up , except my big toes.

Black Toenail: There are several ways your toenail could turn black, including: injury or trauma to the nail or affected toe, fungal infection, repeated trauma from running or athletic, activities, ill-fitting or tight shoes, malignant melanoma (an extremely rare condition) treatment depends on the cause.

Check with your doc: Is it one or two? You want to see a dermatologist to make sure you have no skin cancer like melanoma. Better be safe. Most likely you will be relieved and there will be no cancer. A podiatrist can now clear it up.