Definition

By Mayo Clinic Staff

Blood clots are gel-like clumps of blood. When they form in response to a cut or other injury, they stop the bleeding by plugging the injured blood vessel. These blood clots help the body heal.

But some blood clots form inside the veins without a good reason. They don't dissolve naturally. These clots may require medical attention, especially if they are in the legs, lungs or brain. A number of conditions can cause this type of blood clot.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

We use the data you provide to deliver you the content you requested. To provide you with the most relevant and helpful information, we may combine your email and website data with other information we have about you. If you are a Mayo Clinic patient, we will only use your protected health information as outlined in our Notice of Privacy Practices. You may opt out of email communications at any time by clicking on the unsubscribe link in the email.

March 20, 2025

See also

  1. Dr. Wallace Video
  2. Dr. Mark Truty (surgery, MN) better outcomes with chemo
  3. Buerger disease
  4. Essential thrombocythemia
  5. Mitral valve stenosis
  6. Pancreatic cancer
  7. Pancreatic Cancer
  8. What is pancreatic cancer? A Mayo Clinic expert explains
  9. Infographic: Pancreatic Cancer: Minimally Invasive Surgery
  10. Pancreatic Cancer Survivor
  11. Infographic: Pancreatic Cancers-Whipple
  12. Varicose veins
  13. Endovenous thermal ablation