It seemed like just last night you were able to fit your feet into those gorgeous sandals you got for a steal. But today, your feet just won’t fit and that’s when you notice that something is wrong – they’re swollen. “There are probably 50 different things that can cause feet, ankles, and legs to swell,” says Dr. Britt H. Tonnessen, a Yale Medicine vascular surgeon, according to Prevention. 

While there may be many reasons for the swelling, here are nine possible causes:

1. You’re on or off your feet all day

Whether you’re constantly running errands all day or sitting on a chair for long periods of time, it can cause achy, sore and swollen feet. When you’ve been off your feet especially, the blood goes straight to your feet in a phenomenon known as dependent edema – swelling that’s related to gravity. In order to beat this swelling, propping your feet up on a cushion or pillow can reduce the swelling. Dr. Tonnessen also suggests wearing compression socks. She says, “They go from the foot to the knee and are a little snugger on the foot and ankle to prevent the accumulation of fluid.”

2. You’re healing from an injury

Inflammation caused by a fracture or tendinitis can not only hurt but also lead to extra blood flow and fluid gathering in your injury to help heal it. Staying off your feet and taking the prescribed medication can help reduce the swelling. 

3. You’re consuming too much salt

Salt is one thing that we can’t live without. After all, what will flavor our food perfectly? However, too much sodium can cause your body to retain water which then leads to puffiness and swelling. The American Heart Association recommends that adults take in no more than 2,300 mg of sodium every day, or about a teaspoon of salt per day.

4. You’re above your average BMI and weight

Weight gain can be caused by a lot of things, including medical conditions and medications. So if you’ve recently gained some weight, you’ll notice that your legs and feet are growing larger too. “If you’re sitting a lot, that extra weight in your belly sits right on the groin area, and that can disrupt the lymphatic flow that drains fluid from your legs,” says Dr. Tonnessen. “But even losing just 10 or 20 pounds can make a difference.”

5. You’ve got varicose veins

This is a very common condition that happens when the veins in the leg weaken over time and lose elasticity. As a result, blood that is pumped doesn’t go to the various organs and instead pools in the vein, according to Medical News Today. This can cause swelling in your legs. Keeping your feet elevated for 15 minutes and performing regular exercises can help reduce the effects. 

6. You may have a foot infection

When a swollen foot really hurts upon touch, it could mean that you have a foot infection. According to Health, Dr. Britt Marcussen, assistant professor of family medicine at the University of Iowa Carver College of Medicine says, “The swelling is usually associated with red, hot, sore skin.” Adults with diabetes or certain other diseases are more prone to infections. 

7. You’ve got a blood clot

While most swelling is gradual, if you see a sudden swelling in your leg, especially if it’s just in one leg, then it could point to a blood clot. It’s a condition wherein the clot forms deep in the tissue and it’s called Deep Vein Thrombosis. “This can happen at any age, and it typically happens after someone has been laid up after an injury or hospitalization, or after a long car ride or airplane flight,” says Dr. Tonnessen. Diagnosed using an ultrasound, the immediate treatment includes blood-thinning medication to keep the clot from traveling to other parts of your body, particularly your brain, lungs, and heart. 

While most of these causes can be solved easily, it is best for you to visit the doctor and ensure that you catch any serious medical conditions early on.