“There’s no pain that should be ignored,” says Dr. Jane Andersen, a podiatrist in Chapel Hill, N.C. and a member of the American Podiatric Medical Association. Any type of foot pain — new or prolonged — warrants a visit to your primary care doctor or podiatrist.

Pain in the feet can signal a host of conditions, from fractures to plantar fasciitis (inflammation in the tissue that connects your heel bone to toes), to arthritis. Noting the time of day when the pain occurs can give you a hint as to the cause.

Pain in the morning, when you first get up, can point to arthritis or plantar fasciitis. With both conditions, pain will recede as the foot loosens up throughout the day. A common cause of heel pain, plantar fasciitis often affects runners and people who are overweight. Wearing high heels or shoes that don’t have enough arch support also raises the risk. Andersen often sees people in her practice whose plantar fasciitis is caused by exercising in worn out shoes. “Athletic shoes don’t last very long,” she says. If you can estimate the mileage you put on shoes, then a good rule of thumb is replacing shoes every 350 to 500 miles, or anything over a year old, she says.

Pain that gets worse throughout the day may indicate a fracture, Philbin says. Pain caused by a fracture will recede when resting and worsen when bearing weight. Fractures, or small cracks in the bone, can be caused by overactivity or changes in activity, like trying a new exercise, according to the AAOS. Osteoporosis or other conditions that weaken bones can up the risk of a fracture. Healing fractures requires immobilizing the foot with a boot, and possibly even surgery.

You know to check your body and face for skin cancer, but you probably overlook your feet. However, skin cancer is the most common cancer seen in the foot, says Andersen. If you see “an unusual mole on the top or bottom of your foot or between toes, it should be checked out,” she says. “If you notice anything — a lump or bump — you should see a podiatrist.” Don’t forget to check your toenails, too.

Melanoma, the most deadly type of skin cancer, can occur as dark spots underneath the nails. If you’re not sure whether dark spots are serious or something benign, like dried blood from an injury under your toenail, see your doctor — and know that blood under the nail will grow out, while skin cancer will not, Andersen says.

Numb feet can indicate a host of serious health problems, from poor circulation to alcoholism. Causes of numbness may include:

Peripheral artery disease (PAD), a narrowing of the arteries that reduces blood flow, can result in numbness. PAD is also usually accompanied by leg pain and cold lower legs.

Diabetes affects circulation and blood supply, and numbness is a complication of the disease. “Diabetes is a big thing we worry about,” Andersen says. Neuropathy, a complication of nerves most often caused by diabetes, damages the skin and causes diabetics to lose sensation in their feet. Loss of sensation might mean the person can’t feel their skin breaking down, which can cause ulcerations, infections and sometimes severe infections that require amputations, Andersen says. For many undiagnosed diabetics, neuropathy is often the first sign that they have diabetes, Philbin says.

Numbness can also be related to neurological problems, arthritis or long-standing alcoholism, says Philbin. Although unknown why severe alcoholism over time can numb arms and legs, it’s possible that poisoning of the nerves and poor nutrition associated with heavy alcohol use are to blame, according to MedlinePlus, the web site of the U.S. National Library of Medicine.

While swollen feet can commonly occur after standing for long periods of time, they’re also “indicative of some injuries like stress fractures and tendon tears,” Philbin says. It’s also possible that “something is wrong with the veins or arteries, and they’re not working well enough to control swelling,” he says.

If you experience excessive swelling in the feet with no history of injury, your podiatrist can check your circulation by feeling your pulses, and doing tests to rule out thyroid problems or other issues. Swelling may also be a reaction to a medication or a sign of congestive heart failure, Andersen points out.

Constantly cold feet may be a result of insufficient blood flow. Poor circulation is a complication of diseases such as PAD, which most often affects men over 50. Risk factors include smoking, high blood pressure, heart disease and history of stroke.

Your podiatrist can check your circulation by feeling for pulses in the feet. Coldness along with toes that turn colors — from white or blue to red — may be due to Raynaud’s disease, a common condition in which the blood vessels spasm and constrict in response to cold temperatures.

Itchy, scaly feet may signal athlete’s foot — a fungal infection that usually affects areas in the “moccasin distribution,” Andersen says, meaning on the sides and bottoms of the foot and in between toes. Look for a white, scaly or flaky rash, sometimes accompanied by cracks between the toes that itches and stings or burns.

Athlete’s foot mostly happens when sweaty feet are confined in tight shoes, but is contagious and can also be spread through contaminated surfaces like towels, floors and other shoes, according to the Mayo Clinic.

The condition can lead to fungal toenails, which can get worse and harder to treat as we age since the body can’t fight infections as well, says Andersen. About 50 percent of people in their 70s have fungal toenails, she says. Visit a podiatrist for a proper diagnosis. Most cases can be treated by over-the-counter antifungals, though some may need prescription medications.

If you’ve had a sudden change in your gait, consult your doctor right away. Neurological problems may be the cause — ranging from serious issues like stroke and multiple sclerosis, to more minor problems like a herniated disk in your back.

Changes in the way you walk can affect your health in other ways, too. “If there’s instability in your gait and you’re not walking appropriately because of numbness where you can’t feel the ground, it’s dangerous because it’s a fall risk,” says Andersen.

Sometimes gait change occurs after joint replacements in which slightly more bone is removed in one leg than the other, she says. This can lead to pain in one foot or leg. “Any time you have a painful gait it’s a problem,” Philbin says, and you should see a podiatrist.