Melanoma Signs and Symptoms

Melanoma symptoms often start with noticeable changes to your skin. Most people first notice an unusual mole, blemish, or sore that looks different from others—or one that has changed over time.  

Because early detection can significantly improve outcomes, it is important to regularly check your skin and talk to your dermatologist about any new or unusual spots. 

Melanoma most commonly develops in areas of the body that receive regular sun exposure, such as the face, back, arms, and legs. But it can also occur in hidden places, including under the nails, on the soles of the feet, or inside the mouth, nose, or genitals.

What are the signs and symptoms of melanoma?

More than 80% of melanomas are first noticed by patients or their family, friends, or significant other. That’s why monthly self-skin checks are so important—especially if you have many moles, a history of sun exposure, or a family history of skin cancer.

Common symptoms of melanoma include:

• A new or unusual mole, blemish, or sore 
• A spot that looks different from others on your skin ("the ugly duckling") 
• Changes in the size, shape, or color of a mole 
• Itching, tenderness, or pain in a mole or lesion 
• Bleeding, oozing, or crusting 
• A sore that doesn’t heal 
• Pigmented streaks under fingernails or toenails 
• Discoloration on the palms, soles, or mucous membranes

The ABCDEs of melanoma

Dermatologists use the ABCDE system to help detect early signs of melanoma:

A – Asymmetry: One half of the mole doesn’t match the other. 

B – Border: The edges are uneven, ragged, or notched. 

C – Color: The mole has multiple colors or uneven shades, including brown, black, red, or blue. 

D – Diameter: The spot is larger than 6 mm (about the size of a pencil eraser)—but some melanomas can be smaller. 

E – Evolving: Any change in the mole’s size, shape, color, or behavior (such as itching or bleeding) is a warning sign.

What are the signs of other types of melanomas?

While many melanomas appear on the skin, others develop in less visible parts of the body. These “hidden” melanomas often have different symptoms and may go unnoticed without regular checkups. 

Ocular melanoma (eye)

• Blurry vision or loss of part of your field of vision 
• Floaters or flashes of light 
• A growing dark spot on the iris 
• Changes in the shape or size of the pupil 
• Bulging of the eye or changes in eye movement

Mucosal melanoma (mouth, nose, genital, or digestive tract)

Symptoms depend on where the melanoma develops, and can include:

• Bleeding lumps or pigmented lesions 
• Persistent sores or ulcers 
• Pain, swelling, or discomfort in the mouth, nose, or pelvic area 
• Nasal obstruction or frequent nosebleeds 
• Unusual vaginal discharge or bleeding 
• Rectal pain, bleeding, or hemorrhoids that won’t heal 
• Dentures that no longer fit properly

Acral-lentiginous melanoma (hands, feet, or nails)

• Dark streaks under fingernails or toenails 
• Spots or bruises that don’t heal on the palms or soles 
• Irregular pigmentation on fingers, toes, or nail beds

Signs of melanoma to discuss with your doctor

While self-exams are an important first step, only a trained dermatologist can determine whether a mole or lesion is cancerous. If you notice any new, changing, or unusual spots on your skin—or experience any of the symptoms described above—it’s important to make an appointment with a dermatologist. 

If your doctor notices anything unusual during your appointment, they may recommend additional tests.