Blood clotting is a normal function that occurs when you have an injury. If you scrape your knee, blood clots at the site of the injury so you don’t lose too much blood. But sometimes blood clotting can cause complications.

Sometimes a clot will form inside a blood vessel, which is either an artery or a vein. Clots can happen even when there is no injury. Clots can also fail to dissolve after an injury has healed. This can cause serious complications if not discovered and treated.

Some complications could be serious and even life-threatening, especially if a clot forms in a blood vessel. It’s important to understand the symptoms of clots so you can get treatment before complications occur.

Symptoms of a blood clot

Symptoms vary depending on where in your body the clot is. These include:

Arm or legBrainHeartAbdomenLung
• swelling
• soreness
• sudden pains
• warmth in one spot
• changes in vision
• seizures
• speech impairment
• weakness
• changes in sensation in the face, one arm or leg, or one side of your body
• shortness of breath
• excessive sweating
• chest pains that may extend down the left arm
• nausea
• dizziness
• passing out
• serious abdominal pain
• diarrhea
• vomiting
• blood in the vomitus or stool
• sharp chest pains
• a cough with blood
• sweating
• difficulty breathing
• fever
• a rapid pulse
• dizziness
• passing out

Who is at risk?

You may be at risk for forming a blood clot if you:

  • are obese
  • are a smoker
  • are over the age of 60
  • take oral contraceptives
  • have a chronic inflammatory disease
  • have atrial flutter or atrial fibrillation
  • have congestive heart failure
  • have cirrhosis
  • have cancer
  • have fractures in your extremities, especially the lower extremities or pelvis
  • are pregnant
  • have a family history of clotting disorders
  • are unable to walk
  • sit for long periods of time
  • travel frequently

Complications of a blood clot

A blood clot can form in any blood vessel in your body. It can end up in the lungs, heart, brain, or other areas if it breaks away and travels through the blood. These migrations can lead to serious complications as the clot disrupts the flow of blood to important organs. This can result in heart attack and stroke. Other potential complications include:

Pulmonary embolism: A blood clot that lodges in a pulmonary artery within one of the lungs is a pulmonary embolism. This can result in low oxygen levels in the blood and damage to the lungs, heart, and other organs.

Kidney failure: Blood clots in the kidneys can cause damage and ultimately, kidney failure. Fluids and waste can build up causing a number of other complications including high blood pressure.

Deep vein thrombosis (DVT): DVT occurs when a clot forms in a deep vein in an arm or leg. These can cause symptoms at the site, but can also lead to more serious complications if clots break away and travel to the lungs

Pregnancy complications: Blood clots that form in pregnancy usually occur in the veins of the pelvis or lower extremities. This creates a risk for pulmonary emboli and associated complications as well as secondary premature labor, miscarriage, and maternal death.

How to prevent blood clots

Blood clots can be treated with blood thinning medications. But it’s better to take steps to prevent blood clots from forming because complications can be serious and even fatal if not diagnosed early.

Work to control your risk factors so you can reduce your chances of developing a blood clot. Consider taking the following steps:

  • lose weight if you are obese.
  • stop smoking.
  • tell your doctor about any family history of blood clotting.

It’s important to get treatment and follow your doctor’s instructions for lowering your risk factors. Adopting an anti-inflammatory diet high in omega-3 rich foods, fruits and vegetables, and foods rich in vitamin E may also help.

Be physically active. Immobility is a major factor that can lead to clots forming, especially in the legs. Make a point to get up regularly and walk around if you sit for long periods at a desk or if you travel frequently.

Be aware of any other conditions that may increase your risk for a blood clot, and talk to your doctor about strategies to reduce your risk.


Blood clots can be serious. But they are preventable. Understand your risk factors. And if you are at risk for blood clots, be aware of the symptoms. Catching a clot early is crucial to surviving and avoiding the most severe complications.