The decision to observe or treat a nevus may depend on a number of factors, including cosmetic concerns, irritative symptoms (e.g., pruritus), ulceration, infection, and concern for potential malignancy.

Surgical excision is common and is a very effective mode of treatment.

Most instances of onycholysis without a clear cause will heal spontaneously within a few weeks. The most commonly recommended treatment is to keep the nail dry as much as possible and allow the nail to slowly reattach. Trimming away as much loose nail as can be done comfortably will prevent the nail from being pried upwards. Cleaning under the nail is not recommended as this only serves to separate the nail further. Bandages are also to be avoided. When kept dry and away from further trauma, the nail will reattach from the base upward (i.e., from proximal to distal).

If the underlying cause of the condition is not found and the nail continues to detach despite conservative treatment, the nail bed may begin to form a granular layer of abnormal cells on its surface. After six months of detachment, this layer is likely to prevent the adhesion of any new nail tissue, possibly leading to permanent deformity.

Mole removal risks mainly depend on the type of mole removal method the patient undergoes. First, mole removal may be followed by some discomfort that can be relieved with pain medication. Second, there is a risk that a scab will form or that redness will occur. However, such scabs and redness usually heal within one or two weeks. Third, as in other surgeries, there is also risk of infection or an anesthetic allergy or even nerve damage. Lastly, the mole removal may imply an uncomfortable scar depending on the mole size.

Surgical treatment for an ingrown nail is carried out by a podiatrist, a foot and ankle specialist. This is typically an in-office procedure requiring local anesthesia and special surgical instruments. The surgical approach is the removal of the offending part of the nail plate known as a wedge resection. If the ingrown toenail recurs despite this treatment, destruction of the sides of the nail with chemicals or excision is done; this is known as a matrixcestomy. Antibiotics may be used after the procedure but are not recommended, as they may delay healing. Surgical treatment for ingrown nails is more effective at preventing the nail from regrowing inwards compared to non-surgical treatments.

First, a diagnosis must be made. If the lesion is a seborrheic keratosis, then shave excision, electrodesiccation or cryosurgery may be performed, usually leaving very little if any scarring. If the lesion is suspected to be a skin cancer, a skin biopsy must be done first, before considering removal. This is unless an excisional biopsy is warranted. If the lesion is a melanocytic nevus, one has to decide if it is medically indicated or not

If a melanocytic nevus is suspected of being a melanoma, it needs to be sampled or removed and sent for microscopic evaluation by a pathologist by a method called skin biopsy. One can do a complete excisional skin biopsy or a punch skin biopsy, depending on the size and location of the original nevus. Other reasons for removal may be cosmetic, or because a raised mole interferes with daily life (e.g. shaving). Removal can be by excisional biopsy or by shaving. A shaved site leaves a red mark on the site which returns to the patient’s usual skin color in about two weeks. However, there might still be a risk of spread of the melanoma, so the methods of Melanoma diagnosis, including excisional biopsy, are still recommended even in these instances. Additionally, moles can be removed by laser, surgery or electrocautery.

In properly trained hands, some medical lasers are used to remove flat moles level with the surface of the skin, as well as some raised moles. While laser treatment is commonly offered and may require several appointments, other dermatologists think lasers are not the best method for removing moles because the laser only cauterizes or, in certain cases, removes very superficial levels of skin. Moles tend to go deeper into the skin than non-invasive lasers can penetrate. After a laser treatment a scab is formed, which falls off about seven days later, in contrast to surgery, where the wound has to be sutured. A second concern about the laser treatment is that if the lesion is a melanoma, and was misdiagnosed as a benign mole, the procedure might delay diagnosis. If the mole is incompletely removed by the laser, and the pigmented lesion regrows, it might form a recurrent nevus.

Electrocautery is available as an alternative to laser cautery. Electrocautery is a procedure that uses a light electrical current to burn moles, skin tags, and warts off the skin. Electric currents are set to a level such that they only reach the outermost layers of the skin, thus reducing the problem of scarring. Approximately 1-3 treatments may be needed to completely remove a mole. Typically, a local anesthetic is applied to the treated skin area before beginning the mole removal procedure.

For surgery, many dermatologic and plastic surgeons first use a freezing solution, usually liquid nitrogen, on a raised mole and then shave it away with a scalpel. If the surgeon opts for the shaving method, he or she usually also cauterizes the stump. Because a circle is difficult to close with stitches, the incision is usually elliptical or eye-shaped. However, freezing should not be done to a nevus suspected to be a melanoma, as the ice crystals can cause pathological changes called "freezing artifacts" which might interfere with the diagnosis of the melanoma.

The management of a nevus depends on the specific diagnosis, however, the options for treatment generally include the following modalities:

Mild to moderate cases are often treated conservatively with warm water and epsom salt soaks, antibacterial ointment and the use of dental floss. If conservative treatment of a minor ingrown toenail does not succeed, or if the ingrown toenail is severe, surgical treatment may be required. A "gutter splint" may be improvised by slicing a cotton-tipped wooden applicator diagonally to form a bevel and using this to insert a wisp of cotton from the applicator head under the nail to lift it from the underlying skin after a foot soak.

In approximately half of suspected nail fungus cases there is actually no fungal infection, but only some nail dystrophy. Before beginning oral antifungal therapy the health care provider should confirm a fungal infection. Administration of treatment to persons without an infection is unnecessary health care and causes needless exposure to side effects.

Treatment of manifestations: special hair care products to help manage dry and sparse hair; wigs; artificial nails; emollients to relieve palmoplantar hyperkeratosis.

Most treatments are topical or oral antifungal medications.

Topical agents include ciclopirox nail paint, amorolfine or efinaconazole. Some topical treatments need to be applied daily for prolonged periods (at least 1 year). Topical amorolfine is applied weekly. Topical ciclopirox results in a cure in 6% to 9% of cases; amorolfine might be more effective. Ciclopirox when used with terbinafine appears to be better than either agent alone.

Oral medications include terbinafine (76% effective), itraconazole (60% effective) and fluconazole (48% effective). They share characteristics that enhance their effectiveness: prompt penetration of the nail and nail bed, persistence in the nail for months after discontinuation of therapy. Ketoconazole by mouth is not recommended due to side effects. Oral terbinafine is better tolerated than itraconazole. For superficial white onychomycosis, systemic rather than topical antifungal therapy is advised.

There exist numerous treatments for nail psoriasis but there is little information concerning their effectiveness and safety.

Treatments include topical, intralesional, radiation, systemic, and combination therapies.

- Tacalcitol ointment obtains a significant improvement in all nail parameters, both of the matrix and of the bed.

- Clobetasol nail lacquer and tacalcitol ointment

- 5-fluorouracil. A reported side-effect is yellow nails

- Calcipotriol

- Calcipotriol plus betamethasone dipropionate ointment.

- Efalizumab

- Infliximab

- Golimumab

- Low dose methotrexate

- Intralesional corticosteroid injection

Available studies lack sufficient power to extrapolate a standardized therapeutic regimen.

As of April 2009, an assessment of the evidence for the efficacy and safety of the treatments for nail psoriasis is in progress.

- Infliximab appears to be the most effective treatment for nail psoriasis to date.

- Results from low-dose acitretin therapy show NAPSI score reductions comparable with those studies evaluating biologic drugs for nail psoriasis and suggest that low-dose systemic acitretin should be considered in the treatment of nail psoriasis.

Chemical (keratolytic) or surgical debridement of the affected nail appears to improve outcomes.

As of 2014 evidence for laser treatment is unclear as the evidence is of low quality and varies by type of laser.

As of 2013 tea tree oil has failed to demonstrate benefit in the treatment of onychomycosis. A 2012 review by the National Institutes of Health found some small and tentative studies on its use.

Daily use of hand lotion or hand cream may help prevent the formation of hangnails.

For home treatment, the American Academy of Dermatology recommends washing the hands, clipping the loose piece of skin with a clean nail clipper or nail scissors, and applying over-the-counter antibiotic ointment if the area appears inflamed. Persistent hangnails should be evaluated by a physician.

Treatment for NPS varies depending on the symptoms observed.

- Perform screening for renal disease and glaucoma, surgery, intensive physiotherapy, or genetic counseling.

- ACE inhibitors are taken to treat proteinuria and hypertension in NPS patients.

- Dialysis and renal transplant.

- Physical therapy, bracing and analgesics for joint pain.

- Other surgery treatments such as patella realignment, joint replacement, and the cutting away of the head of radius.

Therapies for metastatic melanoma include the biologic immunotherapy agents ipilimumab, pembrolizumab, and nivolumab; BRAF inhibitors, such as vemurafenib and dabrafenib; and a MEK inhibitor trametinib.

When no pus is present, warm soaks for acute paronychia is reasonable, even though there is a lack of evidence to support its use. Antibiotics such as clindamycin or cephalexin are also often used, the first being more effective in areas where MRSA is common. If there are signs of an abscess (the presence of pus) drainage is recommended.

Chronic paronychia is treated by avoiding whatever is causing it, a topical antifungal, and a topical steroid. In those who do not improve following these measures oral antifungals and steroids may be used or the nail fold may be removed surgically.

Also known as "scoop", "scallop", or "shave" excisional biopsy, or "shave excision". A trend has occurred in dermatology over the last 10 years with the advocacy of a deep shave excision of a pigmented lesion An author published the result of this method and advocated it as better than standard excision and less time consuming. The added economic benefit is that many surgeons bill the procedure as an excision, rather than a shave biopsy. This save the added time for hemostasis, instruments, and suture cost. The great disadvantage, seen years later is the numerous scallop scars, and a very difficult to deal with lesions called a "recurrent melanocytic nevus". What has happened is that many "shave" excisions does not adequately penetrate the dermis or subcutanous fat enough to include the entire melanocytic lesion. Residual melanocytes regrow into the scar. The combination of scarring, inflammation, blood vessels, and atypical pigmented streaks seen in these recurrent nevus gives the perfect dermatoscopic picture of a melanoma. When a second physicians re-examine the patient, he or she has no choice but to recommend the reexcision of the scar. If one does not have access to the original pathology report, it is impossible to tell a recurring nevus from a severely dysplastic nevus or a melanoma. As the procedure is widely practiced, it is not unusual to see a patient with dozens of scallop scars, with as many as 20% of the scars showing residual pigmentation. The second issue with the shave excision is fat herniation, iatrogenic anetoderma, and hypertrophic scarring. As the deep shave excision either completely remove the full thickness of the dermis or greatly diminishing the dermal thickness, subcutanous fat can herniate outward or pucker the skin out in an unattractive way. In areas prone to friction, this can result in pain, itching, or hypertrophic scarring.

Some recommend avulsion of the nail plate with surgical destruction of the nail matrix with phenol or the carbon dioxide laser, if the blood supply is good.

Hangnails can become infected and cause paronychia, a type of skin infection that occurs around the nails. Treatments for paronychia vary with severity, but may include soaking in hot salty water, the use of oral antibiotic medication, or clinical lancing. Paronychia itself rarely results in further complications but can lead to abscess, permanent changes to the shape of the nail or the spread of infection.

The most common treatment, which is cheap and widely available, is to apply a clear, bitter-tasting nail polish to the nails. Normally denatonium benzoate is used, the most bitter chemical compound known. The bitter flavor discourages the nail-biting habit.

Behavioral therapy is beneficial when simpler measures are not effective. Habit Reversal Training (HRT), which seeks to unlearn the habit of nail biting and possibly replace it with a more constructive habit, has shown its effectiveness versus placebo in children and adults. A study in children showed that results with HRT were superior to either no treatment at all or the manipulation of objects as an alternative behavior, which is another possible approach to treatment. In addition to HRT, stimulus control therapy is used to both identify and then eliminate the stimulus that frequently triggers biting urges. Other behavioral techniques that have been investigated with preliminary positive results are self-help techniques, and the use of wristbands as non-removable reminders. More recently, technology companies have begun producing wearable devices and smart watch applications that track the position of users' hands.

Another treatment for chronic nail biters is the usage of a dental deterrent device that prevents the front teeth from damaging the nails and the surrounding cuticles. After about two months, the device leads to a full oppression of the nail biting urge.

Evidence on the efficacy of drugs is very limited and they are not routinely used. A small double-blind randomized clinical trial in children and adolescents indicated that N-acetylcysteine, a glutathione and glutamate modulator, could, in the short term only, be more effective than placebo in decreasing the nail-biting behavior.

Nail cosmetics can help to ameliorate nail biting social effects.

Independently of the method used, parental education is useful in the case of young nail biters to maximize the efficacy of the treatment programs, as some behaviors by the parents or other family members may be helping to perpetuate the problem. For example, punishments have been shown to be not better than placebo, and in some cases may even increase the nail biting frequency.

Onychomatricoma is a cutaneous condition characterized by a distinctive tumor of the nail matrix.

This nail disease can mimic many nail problems and should be examined and biopsied by a dermatologist. In particular, a main concern is the malignant and destructive potential that may exist.

Normal treatment for swelling and any respiratory problems is appropriate. Nutritional supplementation with Vitamin E in some studies has been shown to be effective in controlling nail changes.

Melanonychia is a black or brown pigmentation of the normal nail plate, and may be present as a normal finding on many digits in African-Americans, as a result of trauma, systemic disease, or medications, or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption.

There are two types, longitudinal and transverse melanonychia. Longitudinal melanonychia may be a sign of subungual melanoma (acral lentiginous melanoma), although there are other diagnoses such as chronic paronychia, onychomycosis, subungual hematoma, pyogenic granuloma, glomus tumour, subungual verruca, mucous cyst, subungual fibroma, keratoacanthoma, carcinoma of the nail bed, and subungual exostosis.