Looking down at your toes, you notice that one, or a few, are looking a bit off-color. Whether green, black, or brown, this unsightly scene is enough to ask yourself: Is this discoloration normal? Should I be worried?\nFind out what can cause nail discoloration and when you should talk to a doctor.\nGet expert dermatology care in Pennsylvania, when you need it. Learn more about UPMC eDermatology. \nCauses of Nail Discoloration\nToenails can change color for different reasons; some are more treatable than others. Before you can treat a discolored toenail, you have to know the cause. Common causes of nail discoloration include:\nFungal infection of the nails\nDirt, poor hygiene, and living in a humid area are all causes of a fungal infection in your toenails. Fungal toenail infections can cause discoloration, making your nail appear any of these colors:\n\nYellow\nRed-brown\nGreen\nBlack\n\nIf a fungal infection is causing your nail discoloration, you may have success treating it with an over-the-counter antifungal cream.\nMedical conditions that cause discolored nails\nCertain medical conditions, such as diabetes, poor circulation, or a heart or lung disease, can cause your toenails to change color. Talk to your doctor about any existing conditions you have that could affect the color of your nails.\nNail injury\nIf you play sports, run on a regular basis, or participate in an activity that causes trauma to your feet, your toenails may develop white spots. If the trauma is severe enough, your nail can turn black from damage to the blood vessels and, in time, fall off.\nNail discoloration and age\nAs you age, your toenails, as well as your fingernails, may begin to turn a light shade of yellow. Nail discoloration is a normal part of the aging process.\nYellow nail syndrome\nYellow nail syndrome is a very rare condition. Often associated with lymphedema, it can occur during cancer treatment.\nWhat You Can Do About Discolored Toenails\nIf you develop toenail fungus, you can treat the infection with an antifungal cream or an oral medication. For other causes of toenail discoloration, make sure your feet are well protected and avoid walking barefoot to prevent an injury or infection.\nHere are some tips to prevent discolored toenails:\n\nWear shoes that fit properly to avoid injury\nKeep your toenails trimmed short\nWear clean socks\nDry your feet well after swimming or showering\nAvoid walking barefoot, especially in public places\nAvoid putting on socks or shoes while your feet are damp\nSpray your shoes with an antifungal spray to prevent infection\n\nWhen to See a Doctor for Discolored Nails\nMost of the time, discolored toenails can be treated with over-the-counter medicines or items you already have at home. However, you may need to make an appointment with a dermatologist if you suspect a severe fungal infection or have other symptoms besides toenail discoloration. If you experience bleeding, sharp pain, or swelling, contact your doctor.\nFor more information about treating discolored toenails, contact the UPMC Department of Dermatology or call 412-647-4200.