So you had a whole day without a single peep from your feet. And when you get into bed at night, all of a sudden your feet feel itchy. You scratch the itch and go back to resting. But the itch is still there. So you repeat. Repeat. Get frustrated. Repeat.

Why is it that your feet seem to suddenly itch at night? Not like you're wearing itchy socks. Not like your sheets are any different than they were last night. So what's up?

Certain theories tend to get trotted out about itchy feet at night. "There are some common assumptions about it that probably aren't correct," says Brian S. Kim, M.D., co-director at the Center for the Study of Itch at Washington University School of Medicine. One classic hypothesis is that people are less distracted at night and all of a sudden tune into the itch. "I don't think it's that simple," says Dr. Kim.

That said, it's not entirely clear what a more complex answer is yet. A newer hypothesis is that nighttime itching could be a result of end-of-day changing circadian rhythms, Dr. Kim says. At night, the anti-inflammatory chemicals in your body are lower, and they may have to do with regulating the sensitivity of itching. "You may get a cleaner kind of signal from a nighttime itch," he says.

Evolutionarily, that stronger, cleaner itch signal at night might have served us well. "I'm getting really speculative here, but if you don't move at all at night, you may be more susceptible to getting infestations with mites, or even getting bitten by mosquitoes," says Dr. Kim.

What makes feet itchy?

Ask why people's feet itch and dermatologists take a deep breath, because there can be a huge number of drivers. Some are very simple, others not so much. Causes can include:

Athlete's foot.

"When a patient comes in and complains of itchy feet, the first thing a dermatologist usually does is look between the toes to see if there's redness, cracking, flaking, or scaling," says Shawn Kwatra, M.D., assistant professor of dermatology at Johns Hopkins Medicine. Those often indicate athlete's foot, and remedies include keeping your feet as dry as possible and using an over-the-counter anti-fungal product.

Dry skin.

"As you get older, you have less of an ability to retain water in the outer layer of skin," says Dr. Kwatra. On top of that, since you're walking on your feet all day, they can be thickened and dry, anyway. All of which adds up to extra itch on your feet. Help stop it by applying moisturizing cream—the kind that comes in a jar—on your feet at night. "Cream is more moisturizing than lotion," Dr. Kwatra points out. "The more gooey it is, the more moisturizing it is."

Skin conditions including eczema and psoriasis.

These usually make the rest of your body itchy, and the feet aren't exempt from feeling it.

Other medical problems.

Nerve damage caused by unchecked diabetes can cause itching in the feet, as can liver disease. Sometimes, Dr. Kwatra says, "itch on the body can be a harbinger of underlying illness." Most of the time, itch that hints at an underlying illness won't just be in your feet. "Take it in context with the rest of your health," he says. In other words, not every itchy foot is going to be the sign of a big issue like these, but if itchy feet are a consistent and long-standing problem for you, get yourself checked out, says Dr. Kwatra.

Systems we haven't even figured out yet.

"Itching may be a result of multiple system failures," says Dr. Kim. Itch may not just be one symptom, there may be many forms of itch. "Itch is almost a field of medicine onto itself," he says. And only the surface has been scratched, so to speak.

How to stop itchy feet at night

The toolbox for stopping that annoying itch is pretty straightforward:

  • Use moisturizer. If your feet are extra dry, use heavy-duty creams there. (Check out some of our favorite moisturizers for dry skin.)
  • Consider a product with menthol. The cooling sensation that you get with menthol can help dim the feeling that you need to itch by confusing the nerves that are transmitting the itch signal.
  • Manage your stress. There's likely an itch/stress cycle when things get really bad—itch can trigger a lot of anxiety and stress, and it's likely that that triggers more itch. Even on a more casual itch level, stress probably plays a role, too. "Lots of patients ask me, 'Did my stress cause this?'" says Dr. Kim. "My answer is that I don't think so, but it does aggravate it." (Check out 9 ways to relieve stress here.)

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