What Causes Toenails to Appear Bruised or Discolored? Diagnosis and Treatment

What Causes Bruised Looking Toenails?

Have you noticed dark spots or discoloration on your toenails recently? While it may look like bruising, there are several potential causes behind this change in toenail appearance. Learning what leads to bruised looking nails can help you identify the underlying issue and find the right treatment.

Fungal Infection

One of the most common causes of bruised toenails is a fungal infection. Fungi that infect the nail are called onychomycosis. This condition accounts for about 50% of nail disorders and can make nails look dark, discolored, thickened or brittle.

Fungal infection develops when microscopic organisms called dermatophytes invade the nail bed. As the infection worsens, the nail can take on a dark brown, black, yellow, white or green hue. There is often debris build-up under the nail as well.

Risk factors for fungal nail infections include:

• Athlete's foot
• Walking barefoot in damp areas like pools, showers or locker rooms
• Wearing tight-fitting shoes that don't allow proper ventilation
• Injuries to the nail that allow fungi to enter
• A weakened immune system
• Medical conditions like diabetes or psoriasis

Treating toenail fungus requires prescription oral or topical antifungal medication. Over-the-counter treatments are not strong enough. Removing the infected part of the nail or laser therapy may also be necessary.

Bruising Under the Nail

Sometimes a toenail can become bruised, bloody and discolored after an injury. If the nail bed gets damaged, bleeding can occur underneath the nail plate. This is called subungual hematoma.

Causes of bruising under or around the toenail include:

• Dropping something on your toe
• Stubbing your toe
• Jamming your toe during sports
• Hitting your toe against furniture
• Ill-fitting shoes pressing on the toenail

Bruising is often painful. The toenail may detach from the nail bed until new healthy nail grows in. Subungual hematoma usually resolves on its own. See a doctor if pain is severe or infection develops.

Melanonychia

In some cases, a black or brown discoloration on the toenail is caused by melanonychia. This condition occurs when there is an increase of melanin deposition in the nail. Melanin is the pigment that gives skin and hair its color.

Melanonychia can develop from:

• Genetic predisposition
• Nail trauma
• Radiation exposure
• Chemical exposure
• Medications like antimalarials and cytotoxic drugs
• Systemic illness such as kidney failure

While most cases of melanonychia are benign, sometimes it can indicate a rare type of skin cancer called subungual melanoma. See your doctor to determine the cause of any new nail discoloration or stripes.

Psoriasis

Nail psoriasis is another possible cause of bruised looking toenails. Up to 50% of people with psoriasis will get psoriasis of the nails. Along with pitting, ridging and detachment of the nail, dark patches or streaks can appear.

Psoriasis occurs when the immune system causes inflammation and a rapid buildup of skin cells. What triggers nail psoriasis is not entirely known. It may be linked to psoriatic arthritis.

Nail psoriasis symptoms differ between individuals but may include:

• Discoloration - yellowish-brown, black, white
• Nail pitting
• Leukonychia - white spots on nails
• Splinter hemorrhages - thin, red-black lines
• Nail separation from bed
• Thickened nails
• Crumbling nails

Topical corticosteroids, calcipotriene and tazarotene can help treat nail psoriasis. Phototherapy, oral medications or injections may be prescribed for severe cases.

Vitamin Deficiencies

Certain vitamin deficiencies may also lead to toenail discoloration that resembles bruising. Lack of key nutrients in the diet can affect nail health.

B vitamin deficiencies may cause:

• Spoon-shaped nails (koilonychia) - vitamin B12 deficiency
• White nails with darker rims - biotin deficiency

Other deficiencies linked to nail changes include:

• Pale nails with white spots - zinc deficiency
• White lines/bands - calcium deficiency
• Brittle, cracked nails - iron deficiency

Eating a balanced diet high in fruits, vegetables, lean proteins, dairy, beans, nuts and whole grains can provide adequate nutrition for healthy nails.

Yeast Infection

Although less common than fungal infections, yeast infections can also infect nails and lead to discoloration. Candida albicans is the most common type of yeast that causes infections.

Risk factors for invasive candida nail infections include:

• Diabetes
• Weakened immune system
• Peripheral vascular disease
• Frequent exposure to moisture

Signs of a yeast infection may include:

• Thick, discolored nails
• Brittle, crumbly nails
• Debris under nail
• Nail detachment
• Cottony growth on top of nail

Oral antifungal medications are used to treat chronic yeast infections affecting multiple nails. Keeping nails trimmed and dry can prevent infection.

What to Do About Discolored Toenails

Here are some tips for dealing with bruised looking toenails:

• See your doctor - they can determine the cause and proper treatment
• Trim nails straight across to avoid ingrown toenails
• Wear proper fitting shoes and clean cotton socks
• Apply antifungal cream if fungus is present
• Take injured nails seriously to avoid infection
• Eat a balanced diet with plenty of vitamins
• Practice good foot hygiene and keep feet dry

While bruised looking nails are often harmless, some causes can lead to pain, permanent damage and other complications. Have any major nail changes evaluated right away. Prompt treatment can restore the health and appearance of your toenails.

When to See a Doctor for Discolored Toenails

In most cases, minor toenail discoloration is nothing to worry about. Bruises, stains and flecks often resolve on their own. However, there are some circumstances when you should see a podiatrist or dermatologist for evaluation of nail changes:

• The nail becomes very painful, swollen or hot to the touch
• Discoloration spreads quickly
• New black or brown streaks appear
• You have a history of injury to the toe area
• Signs of infection develop like drainage, foul odor or increased thickness

Seek prompt medical care if:

• You experience pain, numbness or tingling in the toe
• Redness and inflammation spread beyond the nail
• Any change in nail color or texture affects multiple nails
• The nail becomes very loose or falls off

Dermatologists have special training to diagnose and treat hundreds of nail conditions. They can perform tests and imaging to pinpoint the exact cause of any toenail problems.

Causes of Toenail Discoloration that May Require Treatment

Here are some specific disorders and diseases that warrant medical evaluation if they cause nail discoloration:

• Fungal infections - Oral antifungal drugs may be needed for severe fungal toenail infections. Topical treatments alone often don't penetrate deep enough.
• Psoriasis - Immunosuppressant drugs, biologic therapy and phototherapy can treat severe nail psoriasis that doesn't respond to topical creams.
• Melanoma - Dark longitudinal streaks or spreading pigmentation may indicate this serious skin cancer. Early diagnosis is key.
• Diabetes - Toenail changes can signify uncontrolled blood sugar. Strict glucose control helps minimize complications.
• Kidney disease - Half and half nails (dark outer edges with white halves) can signal kidney failure. Dialysis or transplant may be needed.
• Lichen planus - This inflammatory condition can cause ridged, brittle nails. Corticosteroids and other drugs offer relief.
• Yellow nail syndrome - Yellow, thickened, slow-growing nails point to lung disease, lymph edema or other systemic disorders.

Don't try to self-diagnose any nail problems. See a doctor whenever there are changes in color, shape, texture or thickness. Early treatment helps prevent permanent damage and disability.

Diagnostic Tests for Toenail Problems

Doctors have a variety of tools at their disposal to figure out what is going on when nails look bruised, bloody or discolored:

• Physical exam - Careful inspection of nail shape, consistency and appearance.
• Medical history - Discussion about risk factors, family history, related symptoms, lifestyle and social factors.
• Lab tests - Blood work and cultures to uncover any underlying illness.
• Fungal tests - Clippings scrutinized under a microscope or sent for fungal culture.
• Biopsy - Removal of nail tissue for examination under a microscope.
• Imaging - X-rays, CT scans or MRI to evaluate for bone infection or cancer.

Based on the findings from these diagnostic tests, doctors can pinpoint the specific cause of the nail issues and outline the proper treatment plan. This might include medication, surgery, lifestyle changes or management of related conditions.

Home Treatment for Discolored Toenails

Unless there are signs of infection, severe pain or spreading changes, you can try some simple home treatments while waiting to see a foot doctor:

• Soak feet in warm water - Helps soften thickened nails.
• Apply antibiotic cream - Prevents infection in injured nails.
• Take OTC pain relievers - Reduces discomfort from bruising or trauma.
• Trim nails - Removes loose parts to promote new growth.
• Use antifungal polish or cream - May clear up fungal infections.
• Keep feet clean and dry - Discourages fungi and yeast overgrowth.

See your primary care provider first if you don't have a podiatrist or dermatologist. They can make a preliminary evaluation and refer you to a specialist for further diagnosis and treatment if needed.

Don't try to dig out bruised areas or pull off discolored parts of nails at home. This can worsen the problem and raise the risk of infection. Any nail removal should be done properly by a medical professional.

With prompt attention and appropriate care, unhealthy looking nails can be restored to their normal shape, color and condition. Don't ignore toenails that seem bruised or bloody. Determine the underlying cause so proper treatment can begin.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.