5 Signs You Might Have a Blood Clot

Learn how to spot the symptoms of deep vein thrombosis and pulmonary embolism before it’s too late.

Think about the last time you got a cut.

After a few minutes, the bleeding probably subsided, letting your body begin the healing process. You can thank your blood’s clotting system.

When everything’s running smoothly, there’s a fine balance between the proteins and enzymes that form the clots and the ones that break them down, explains Mounir Haurani, M.D., a vascular surgeon at Ohio State University Wexner Medical Center. But if a triggering factor occurs—say, an injury to the vein or prolonged immobility, like if you’ve been in the hospital—it can disrupt that balance, making blood clot abnormally.

When that happens, you can develop blood clots in the deep veins of your body, usually in your legs. This is called deep vein thrombosis (DVT). People 60 years and older are at higher risk of DVT, along with those who smoke, are overweight, or take hormone replacement therapy.

These blood clots are different from the ones that form in your arteries and contribute to heart attack, Dr. Haurani says. But that doesn’t mean they’re any less serious. In fact, a blood clot in your veins can be deadly.

“The most immediate concern is the potential risk for pieces of that clot to break off and travel to the lungs, a condition called pulmonary embolism—which can be fatal,” says Kim J. Hodgson, M.D., chair of vascular surgery at Southern Illinois University Medicine.

A blood clot in your pulmonary artery can block the exchange of oxygen from your lungs to your heart, meaning your system will lack the oxygen it needs to function, Dr. Haurani says. A large clot can also force the heart to work harder in order to pump blood around it, possibly leading to heart failure.

Staying active, eating well, and working with your doctor to manage any risk factors can help prevent blood clots. Another great way to protect yourself is to become familiar with the warning signs of DVT and pulmonary embolism (PE) so you can get help fast if the condition strikes. Here’s what to watch for.

1. Swelling in One Leg

Swelling is a common sign of DVT, and you’ll usually notice it come on suddenly—and in only one leg, Dr. Hodgson says.

Most commonly, you’ll notice the swelling in your foot or ankle. But if it’s a really big clot, the swelling can go up your whole leg.

“Your blood backs up,” explains Dr. Haurani. “It’s trying to get up through the veins that are now filled with clots, so it can’t get through as easily as it normally would.”

This blood backup can cause inflammation, leading to a fluid leak around the blood vessels and subsequent swelling.

2. Leg Pain That Starts in Your Calf

DVT can cause a heavy, aching pain in your leg, which often comes with tenderness on your calf, Dr. Hodgson says.

“It can range from a dull ache—almost like a muscle soreness you get after working out—to a pretty severe pain,” Dr. Haurani says. “It just depends on which vein and the extent of the clot that’s in there.”

Pain caused by DVT also tends to get worse when you stretch your toes upward, since your calf muscles are squeezing and pushing on the inflamed, irritated veins where the clot is. Your doctor might ask you to stretch your toes to check for DVT, Dr. Haurani says.

3. Red or Discolored Skin on Your Leg

In most cases of DVT, you won’t see anything at all. But in severe cases, you may see redness in the skin above the clot. That’s due to inflammation, Dr. Haurani says.

You may also see a bluish discoloration on the affected foot, which can occur because of congestion caused by the blood backup, he explains. Other veins in the affected area may also become more prominent.

4. Your Heart Is Racing

Now we’re talking PE. If a clot is hindering blood flow in your pulmonary artery, your heart has to work harder to try to push the blood around it.

“That’s why it picks up how fast it has to pump,” Dr. Haurani says. “If you’re not getting enough oxygen to your system, the heart will compensate by beating faster to help circulate what you do have.”

As a result, you may feel like your heart is racing or beating too fast, or you may even feel short of breath.

5. You Have a Strange Cough

With PE, you might also feel a need to cough, which comes on without any respiratory infection. The cough usually feels like a tickle, Dr. Haurani says.

But in severe, late cases of PE, you might experience a bloody cough. “That’s from actual death of lung tissue,” Dr. Hodgson says. Your cells can die as a result of the lack of oxygen.

Notice Something? Here’s What to Do

If you’re experiencing any signs of DVT (numbers 1, 2, and 3), call your doctor as soon as possible for a same-day appointment, Dr. Haurani says. If your doctor can’t fit you in, head to the emergency room or an urgent care facility where they have ultrasound capabilities, which they’ll use to check for a clot.

If you notice signs of PE (numbers 4 and 5), it warrants an immediate trip to the ER. There, doctors will likely perform a CT scan of your lungs to check for a clot.

If you are diagnosed with DVT, the standard treatment is an anticoagulation medication, or a blood thinner, Dr. Hodgson says. If you don’t develop another one, you should be able to be weaned off the meds in three to six months.

But people who experience one blood clot are at greater risk of getting another one, Dr. Hodgson adds. If that’s the case, you may have to take anticoagulants regularly.

Take Your Favorite SilverSneakers Classes Online!

SilverSneakers members can access live fitness classes and wellness workshops through SilverSneakers LIVE. See the latest schedule and RSVP for classes here.

Not a member? If you have a Medicare Plan, it may include SilverSneakers—at no additional cost. Check your eligibility instantly here.