Underarm tissue is sensitive and can be prone to infection, shaving irritation or skin disorders. Some of these issues lead to pigmentation problems on the underarms. Removing dark spots from underneath your arms is possible, however, and you can return your skin to its normal color. Determining the cause of your discoloration is key to finding a successful treatment.

1. Throw out your deodorant and use an antiperspirant instead. Deodorants can contain toxic substances that can react with skin or irritate and discolor it when used repeatedly.

2. Wax your underarms to remove the hair deep down. Shaving leaves the hair beneath the skin still intact, often leaving behind an unattractive shadow.

3. Lather up your underarms with a shaving cream if you do shave your underarms. Use a shaving cream to provide a smooth surface and to minimize skin irritation that can result in discoloration.

4. Treat fungal infections. The underarms are prone to infection, so if you notice your armpits are extra itchy, you may require treatment with a steroid cream.

5. Visit your doctor to determine whether you have a medical condition such as acanthosis nigricans. This condition occurs when parts of the skin thicken over time, leaving areas darker than the rest of the body. It is common in those with diabetes and in those who are overweight. Acanthosis nigricans can be treated with Retin-A, or alpha or beta hydroxy acids. Other causes of dark underarms could be pituitary gland disorders, thyroid conditions, Addison disease, or use of certain medications such as oral contraceptives or cholesterol drugs.