Most people probably don’t think about blood clots on a regular basis. But with reports of a small number of people developing blood clots after receiving either the Johnson & Johnson vaccine or the AstraZeneca COVID-19, many people are now wondering what the warning signs are.
There are several different variations of blood clots, each with its own set of red flags and treatment options. They can form for several reasons, including medications, lifestyle factors and other health conditions and can occur in different parts of the body.
That being said, blood clots can cause serious injury or can be fatal if left untreated. If you’re worried – whether it’s a vaccine or, more likely, something else – read on for signs and advice on what to do if you think you’re in danger.
Symptoms of blood clots
Blood clots can come from veins or arteries. There are two main types of blood clots you need to know about and each can lead to your own set of potential complications. One type is called a thrombus, which is a stationary clot. They block blood flow to the part of the body where the clot appears. Another type, called an embolus, is a blood clot that can rupture. These are especially dangerous because they can travel to other parts of the body – such as the heart or lungs – and can cause serious injury.
The symptoms of blood clots vary depending on the type. When the clot is stationary, such as deep vein thrombosis (a standing clot), you may have:
- Heat and redness where the clot is – usually in the leg or arm
- Swelling
- Pain near the site of the clot
- Numbness or weakness
- A change in your mental state
If the clot has traveled, leading to complications such as a pulmonary embolism (a clot that has moved to the lungs), you may experience symptoms, including:
- Sudden breathing
- A cough, with or without blood
- Glossy, pale or blue skin
- Excessive sweating
- Anxiety
- Weakness
- Nausea or vomiting
Blood clots can affect your arms, legs, heart, lungs, kidneys and brain, depending on where they form and where they move in the bloodstream.
A handful of people who have received the Johnson & Johnson vaccine have developed complications from a clot originating in the veins near the brain, called cerebral venous sinus thrombosis or CVST. This problem is seen in combination with low levels of platelets in the blood. (Several people who received the AstraZeneca shot experienced clots caused by the same problem, but since the AstraZeneca dose is not yet approved for use in the United States, this story will focus on J&J.)
Symptoms associated with this type of clot complication include severe headache, abdominal pain, leg pain or shortness of breath within three weeks of vaccination, according to the Centers for Disease Control and Prevention and the Food and Drug Administration.
A few important notes when it comes to the J&J vaccine: blood clots after shooting seem to be extremely rare – so far, there are only six reported cases out of almost 7 million doses of vaccine that have been distributed – and they have occurred within 13 days after vaccination. You have a higher risk of developing blood clots from a real COVID-19 infection.
“Just remember that COVID-19 causes blood clots,” infectious disease expert Amesh Adalja told HuffPost in a separate story. COVID-19 also causes blood clots at a higher rate than the vaccine.
Experts point out that the vaccine could change the game of the pandemic, and a major reason for disrupting distribution is to inform healthcare providers about identifying, treating and reporting the problem. Don’t let this stop you from getting vaccinated against coronavirus.
What to do if you suspect you have a blood clot and how to prevent it
First, seek emergency medical attention immediately. Blood clots can be severe or fatal, so if you suspect you have one, it is crucial to address it. When in doubt, call 911 or go to the emergency room – especially if you have the symptoms listed above, along with chest pain or breathing problems.
Once you are with a health care provider, let them know about any history of medical conditions, medications, or recent vaccinations. This is especially important if you have just received the Johnson & Johnson COVID-19 vaccine, as the treatment for this particular clotting problem is different from what doctors normally do to treat blood clots.
In the long run, talk to your doctor about reducing your overall risk of blood clots. Tell them about any family history of the problem.
Certain lifestyle factors can increase your chances of bleeding. For example, being inactive or immobile for long periods of time – such as during a long flight or during bed rest – can contribute. Smoking and obesity can increase your risk.
Medications such as birth control and some HIV treatments list blood clots as a potential side effect. Conditions such as autoimmune disorders, pregnancy and cancer have also been associated with clotting, according to the American Heart Association.
If you are going to travel or in a situation where you will remain immobile for a long time, make sure you move, stretch and move your legs frequently to improve blood flow – especially in calves. You can also benefit from wearing compression socks. For other prevention methods, talk to your doctor. Depending on your health history and current diagnoses, your doctor may suggest certain treatment options that can help you deal with any of these potential complications. This can include a diet plan, exercise, medication or all of the above.
If you suspect you’re dealing with a blood clot, don’t postpone it. It is better to approach what turns out to be nothing than to ignore what turns out to be something. And it’s worth paying attention to your health.