Your toenails serve a purpose, which is to protect your toes. They’re made from keratin, which is the same protein that makes up your skin, hair, and fingernails. It’s keratin that makes them tough and resilient to daily wear and tear.

Friction from your shoes, your level of physical activity, and the heat and moisture they’re exposed to can wreak havoc on your toenails, as can some health conditions.

Pain, itching, and discoloration are just some of the signs of toenail problems.

There are a number of toenail abnormalities that can cause anything from pain to a change in a toenail’s appearance.

Here’s a look at some common toenail problems, what causes them, and their symptoms.

Toenail fungus

Nail fungus, or onychomycosis, is a common condition. About 10 percent of people are affected. The older you are the more likely you are to experience it. Half of all people over age 70 develop this infection.

You may first notice a white or yellow spot under the tip of a toenail. As the fungal infection makes its way deeper into the nail, your nail will become discolored and thicken.

Your nail may also crumble and become jagged at the edge, and spread to other toenails. It can also spread to the surrounding skin.

Toenail fungus can be caused by a fungal infection on your foot or from walking barefoot where someone else with an infection has walked, such as saunas or locker rooms.

Fungi thrive in dark and damp environments, so people whose feet remain wet for extended periods have an increased risk of toenail fungal infections. This can happen when wearing the same sweaty shoes or boots every day or working in wet conditions.

People with diabetes are also at high risk for this infection.

Symptoms

If you have toenail fungus, one or more of your toenails may become:

  • discolored, usually white or yellow
  • thickened
  • misshapen
  • brittle or crumbly
  • foul-smelling

Ingrown toenail

Ingrown toenails are one of the most common and most painful toenail problems. It occurs when the corner or side of your toenail grows into the flesh.

This can be caused by:

  • cutting your toenails too short
  • cutting your toenails on a curve instead of straight across
  • injuring your toenail
  • having unusually large or curved toenails

Symptoms

If you have an ingrown toenail, you may experience:

  • redness and pain along the side of the nail
  • swelling around your toenail
  • pus draining from your affected toenail

Toenail trauma

Toenail trauma can happen several ways, including:

  • stubbing your toe
  • dropping something heavy onto your foot
  • wearing ill-fitting shoes
  • picking at nails

Activities such as running or ballet dancing may also cause trauma to the toenail, as can a poorly performed pedicure.

Injuring a toenail can result in a collection of blood under the nail, called subungual hematoma. Other damage can include a partially or completely separated nail or injury to the underlying bone.

Symptoms

Symptoms of toenail trauma depend on the type of injury and may include:

  • pain or throbbing
  • dark red or purple spot under the nail
  • split or torn nail
  • nail lifting away from the skin
  • thickening of the toenail
  • discoloration
  • bleeding

Clubbed nails

Nail clubbing refers to changes under and around the toenails that cause your toes to take on a widened, club-like appearance.

Clubbing is most often caused by an underlying medical condition, such as heart disease, lung disease, gastrointestinal disorders, and cancer. It can also be an inherited trait in some people.

Clubbing can develop gradually over weeks or years, depending on the cause.

Symptoms

Symptoms of clubbed nails may include:

  • widening and rounding of the toenails
  • downward curving of the toenails
  • pronounced angle between the cuticles and nails
  • softening of the nail beds
  • nails that appear to be floating
  • bulging of the tips of the toes

Discoloration of the nail plates

Discoloration of the nail plates is usually the least worrisome of toenail problems.

Your nails are susceptible to discoloration from substances you come into contact with. Nail polish, dye from your shoes, and other products containing dye can stain your nails.

Drugs, including some cancer drugs, antibiotics, and those used to treat autoimmune disorders, can also cause discoloration of your nail plates.

Discoloration is usually not painful and will improve when your nail grows out or when you stop taking the medication or using the product that caused the discoloration.

There is a rare medical condition that can cause your nail plates to turn white.

Symptoms

Other than the discoloration, there aren’t usually any other symptoms associated with discolored nail beds.

Nail-patella syndrome

Nail-patella syndrome is a rare condition that affects an estimated one in 50,000 people. It causes changes in the nails, kneecaps, hip bone, and elbows. The most common symptom is underdeveloped or missing fingernails and toenails. It caused by a genetic mutation.

Symptoms

The following are some of the symptoms of this rare condition:

  • underdeveloped fingernails and toenails
  • missing fingernails and toenails
  • ridged or split fingernails and toenails
  • discolored nails
  • small, deformed, or missing kneecaps
  • underdeveloped or deformed elbows
  • knee and elbow pain
  • small bony growths on the hip bones (iliac horns)

Leukonychia

Leukonychia is the whitening of the nail plate. The condition can be divided into types based on the extent of the whitening:

  • Leukonychia striata are white streaks on the nail.
  • Leukonychia partialis is a partial whitening of the nail.
  • Leukonychia totalis is the complete whitening of the nail.

It is believed white streaks that form on the nail are due to problems with how the nail makes keratin. Whitening of the nail can be caused by underlying medical conditions or injury to the toenails.

An inherited gene mutation, certain medical treatments, such as chemotherapy, and heavy metal poisoning can also cause leukonychia. In some cases, an underlying cause is not found.

Symptoms

Symptoms of leukonychia include:

  • white spots on the nails
  • partial whitening of the nails
  • complete whitening of the nails

Red or black lines down the nails can be signs of a variety of serious infections and medical conditions, including cancer. See your doctor if you notice these types of changes.

The treatment of toenail problems depends on the issue and its cause.

Toenail fungus

Fungal nail infections can be difficult to cure and usually require prescription antifungal pills. In some cases, removing the nail also may be recommended.

It takes several months for a fungal nail infection to go away. You can help prevent toenail fungus by:

  • keeping your feet clean and dry
  • avoiding walking barefoot in public showers, pools, or locker rooms
  • not sharing nail clippers
  • choosing nail salons that are licensed and sterilize their instruments
  • properly managing your blood sugar levels if you have diabetes

Ingrown toenail

Your doctor may need to lift the nail or perform a partial or complete removal of the nail, depending on the severity of your symptoms. Wearing proper-fitting shoes and trimming your toenails straight across and not too short can help you prevent an ingrown toenail.

Toenail trauma

Treatment depends on the type of trauma and extent of the injury. Treatment options may include surgery and medication.

Other causes of toenail problems

Treatment for other causes of toenail problems, such as clubbed nails and leukonychia, requires treating the underlying condition.

See your doctor about any abnormal changes to your toenails or if you experience signs of infection, such as redness, severe pain, or drainage of pus. Any red or black lines down the nails also require an evaluation by your doctor.

Your toenails experience daily wear and tear, making toenail problems quite common. Taking care of your toenails with proper hygiene and properly fitted footwear can help keep your toenails strong and healthy.