Patient education: Lowering the risk of a blood clot (The Basics)

What is a blood clot? — Normally, the body is protected from bleeding because the blood vessels seal over, or "clot," after an injury. The clot is made by proteins and cells in the blood. Sometimes, these proteins and cells form a clot inside a blood vessel.

Blood clots can be dangerous because they can stop blood from flowing. They can also break off and travel in the bloodstream to another part of the body, like the brain or the lungs. If this happens, it can be serious and even lead to death.

Some situations increase a person's risk of blood clots. If you are at risk, it's important to know the signs of a blood clot. There are also things you can to do lower your risk.

What increases the risk of a blood clot? — You are at a higher risk for a blood clot if you:

●Have had a blood clot before

●Recently had surgery

●Have a central line (a special kind of IV that goes into a blood vessel near the heart)

●Had an injury or problem that keeps you from being able to walk or move around

●Are pregnant

●Take certain medicines like birth control pills, hormones, or chemotherapy

●Have a serious illness like COVID-19 or cancer, or have problems with your bone marrow, heart, intestines, kidneys, or liver

●Are getting older

●Have been traveling and sitting for more than 4 hours at a time, especially on an airplane

●Smoke

●Have excess body weight

How do I lower my risk of a blood clot? — It might not be possible to prevent a blood clot. But there are some things that can lower your risk:

●Your doctor might prescribe a medicine called an "anticoagulant." These are sometimes called "blood thinners." Some anticoagulants come as a pill, and others come as a shot. If you take an anticoagulant:

•Take your medicine exactly as instructed. It's very important to take the right dose. Too much can cause bleeding, and too little can allow your blood to clot.

•Talk to your doctor about any other medicines you take, including aspirin. Some medicines can change how anticoagulant medicines work. This includes certain over-the-counter medicines, herbal products, and supplements.

●Some general tips to lower your risk of a blood clot:

•If you spend a lot of time sitting, try to stand up and walk around at least every 1 to 2 hours. Avoid sitting with your legs crossed. If you can't get up, bend and straighten your knees and ankles, and wiggle your toes.

•When driving or riding in a car, try to stop every 1 to 2 hours to get out and stretch your legs.

•If you travel by plane, move your arms and legs regularly. Walk around and stretch your legs at least once every hour.

•Wear loose-fitting clothing around your legs and waist.

•Wear elastic or compression stockings. This can improve blood flow in your legs.

•Drink plenty of fluids to avoid dehydration.

•Avoid alcohol and medicines that make you sleepy. These can affect your ability to move around.

•Stop smoking or using tobacco products. If you are having trouble quitting, at least try to cut back. Your doctor or nurse can help you.

•If you have excess body weight, talk to your doctor or nurse about how to lose weight in a healthy way.

●Some tips if you are in the hospital or planning surgery:

•Talk to your doctor if you take any type of hormone therapy, such as birth control pills. They might have you stop taking this medicine for a time before and after surgery.

•Talk to your doctor about all other medicines you are taking. You might have to stop some other medicines before surgery.

•You might use a special machine that squeezes and releases your legs. This helps keep blood moving in your legs.

•You might be asked to get out of bed soon after a surgery or while being treated for an illness.

•Walking can speed up recovery. It can also help prevent blood clots.

●Some tips for when you are in bed or in a chair:

•Prop your legs on a pillow when in bed and on a chair or footstool when you sit. Make sure that your lower legs are supported, not just your knees (figure 1).

•To help increase blood flow to your lower legs, point your toes and then bring them back toward your knees. Repeat this motion 10 times or more at least each hour while you are awake.

•Do not cross your legs.

When should I call the doctor? — Call for emergency help right away (in the US and Canada, call 9-1-1) if:

●You feel short of breath or have trouble breathing.

●You have sharp or severe chest pain when you breathe.

●You are coughing up blood.

●You have signs of stroke, like sudden:

•Numbness or weakness of the face, arm, or leg, especially on 1 side of the body

•Confusion, or trouble speaking or understanding

•Trouble seeing in 1 or both eyes

•Trouble walking, dizziness, or loss of balance or coordination

•Severe headache with no known cause

Call the doctor or nurse for advice if:

●You have new or worsened swelling in your arm or leg.

●Your arm or leg becomes numb or very painful to touch.

●Your leg hurts when you walk, or your arm hurts when you move it.

●Your arm or leg turns blue or gray.

●You discomfort when you take a deep breath.

More on this topic

Patient education: Deep vein thrombosis (blood clot in the leg) (The Basics)
Patient education: Pulmonary embolism (blood clot in the lung) (The Basics)
Patient education: Choosing an oral medicine for blood clots (The Basics)
Patient education: Taking oral medicines for blood clots (The Basics)
Patient education: Superficial vein phlebitis and thrombosis (The Basics)
Patient education: Staying healthy when you travel (The Basics)
Patient education: What can go wrong after a heart attack? (The Basics)
Patient education: Duplex ultrasound (The Basics)
Patient education: Factor V Leiden (The Basics)

Patient education: Deep vein thrombosis (DVT) (Beyond the Basics)
Patient education: Pulmonary embolism (Beyond the Basics)
Patient education: Lower extremity chronic venous disease (Beyond the Basics)
Patient education: Warfarin (Beyond the Basics)
Patient education: General travel advice (Beyond the Basics)