Skip to content

7 Signs You've Got a "Deadly" Blood Clot Inside You

Here are the symptoms people are experiencing, according to the CDC. 
FACT CHECKED BY Alek Korab
Woman feeling bad and trying to sleep

One week ago, the CDC and FDA recommended putting a pause on the administration of Johnson & Johnson's Janssen COVID-19 Vaccine after some people experienced severe blood clots, Cerebral Venous Sinus Thrombosis with Thrombocytopenia, shortly after receiving it. In new guidance, the CDC has revealed the seven signs of the life-threatening health condition to look out for. 

The CDC explains that while the risk is low of developing a blood clot post vaccination, that a handful of people have reported one. "Of the nearly 7 million doses administered so far in the United States, a small number of reports of a rare and severe type of blood clot have been reported in people after receiving the J&J/Janssen COVID-19 Vaccine," they write in the new guidance. 

They added that all of the people who reported the blood clot were women between the ages of 18 and 48, with symptoms occurring six to 13 days after vaccination. 

They also confirmed that as of April 13, 2021, "of the more than 180 million doses administered so far of the Pfizer-BioNTech or Moderna vaccines, no reports matching those associated with the J&J/Janssen vaccine have been received." Read on to hear about the 7 symptoms—and to ensure your health and the health of others, don't miss this urgent news: Here's How You Can Catch COVID Even If You're Vaccinated.

1

You May Have a Severe Headache 

Young woman have headache migraine stress or tinnitus
iStock

You may have a headache, and it will be "severe"—these may "range from cluster headache such as onset, worst headache of life, migraine-like headache, exploding headache, chronic tension headache, chronic daily headache, and thunderclap headache," according to one study.

2

You May Have New Neurological Symptoms

dizzy
Shutterstock

"If you have cerebral venous sinus thrombosis: Respond quickly to symptoms like headaches, blurry vision, fainting, losing control of a part of your body, and seizures. If you have the above symptoms, have someone take you immediately to the emergency room or call 911 for help," says Johns Hopkins.

3

You May Have Severe Abdominal Pain

Shutterstock

One Cerebral Venous Sinus Thrombosis patient—unrelated to the vaccines—had a "mood disorder, infrequent migraine without aura, GERD, and ulcerative colitis presented to the emergency department with four weeks of abdominal pain, hematochezia, and an unintentional 28-pound weight loss over those four weeks."

4

You May Have Leg Swelling

Thigh pain or muscle twitching or muscle cramp.
Shutterstock

"If a blood clot forms in a deep vein, it can block the flow of blood, which prevents the tissues from draining properly. This causes excess fluid accumulation, swelling, warmth and discomfort in the leg. A blood clot in a deep vein may also break off and travel back to the heart and into the lungs," says Lifebridge Health.

5

You May Have Tiny Red Spots on the Skin (Petechiae)

woman worrying about her skin
Shutterstock

"Petechiae are pinpoint, round spots that appear on the skin as a result of bleeding. The bleeding causes the petechiae to appear red, brown or purple. Petechiae (puh-TEE-kee-ee) commonly appear in clusters and may look like a rash. Usually flat to the touch, petechiae don't lose color when you press on them," says the Mayo Clinic. This issue "may start as ischemic neuronal damage, petechiae later merging into large hematomas," says a study.

6

You May Have New or Easy Bruising

A male physiotherapist examining mans back in the medical office.
Shutterstock

"Easy bruising sometimes indicates a serious underlying condition, such as a blood-clotting problem or a blood disease," says the Mayo Clinic. "See your doctor if you:

  • Have frequent, large bruises, especially if your bruises appear on your trunk, back or face, or seem to develop for no known reasons
  • Have easy bruising and a history of significant bleeding, such as during a surgical procedure
  • Suddenly begin bruising, especially if you recently started a new medication
  • Have a family history of easy bruising or bleeding"

7

You May Have Shortness of Breath

Woman in the casual wear raise her hand over her heart.
Shutterstock

Shortness of breath " typically appears suddenly and always gets worse with exertion," says the Mayo Clinic. It can also include difficulty breathing.

8

You May Have a Backache

Woman sitting on the bed in the bedroom.
iStock

The CDC is recommending doctors look out for "severe headache, backache, new neurologic symptoms, severe abdominal pain, shortness of breath, leg swelling, petechiae (tiny red spots on the skin), or new or easy bruising" and urges they "obtain platelet counts and screen for evidence of immune thrombotic thrombocytopenia."

RELATED: Most COVID Patients Did This Before Getting Sick

9

What to Do if You Experience These Symptoms

Woman have her blood pressure checked by female doctor.
Shutterstock

If you experience any of them, "contact your healthcare provider and seek medical treatment urgently."

The risk of developing the condition is higher in the first three weeks after getting the vaccine and decreases over time. "If you received the vaccine more than three weeks ago, the risk of developing a blood clot is likely very low at this time," they explain. "If you received the vaccine within the last three weeks, your risk of developing a blood clot is also very low and that risk will decrease over time." So get vaccinated when it becomes available to you, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.