Sinus Thrombosis (Venous Sinus Thrombosis) (Sagittal Sinus Thrombosis)

Sinus thrombosis is a rare type of blood clot that occurs inside the venous sinuses, which are the veins that drain blood from your brain. Sinus thrombosis is a rare cause of stroke and can be difficult to diagnose because symptoms vary from person to person depending on the location of the clot.

UPMC neurosurgeons are experts at surgical and nonsurgical approaches to treat all types of sinus thrombosis. Our team will recommend the best approach — or combination of approaches — to treat your condition and reduce your risk of complications.

On this page:

• What Is Sinus Thrombosis?
• What Are the Symptoms of Sinus Thrombosis?
• How Do You Diagnose Sinus Thrombosis?
• How Do You Treat Sinus Thrombosis?

What Is Sinus Thrombosis?

Sinus thrombosis is a rare type of blood clot that occurs inside the venous sinuses, which are the veins that drain blood from your brain. Sinus thrombosis is a rare cause of stroke and can be difficult to diagnose because symptoms vary from person to person depending on the location of the clot.

What are the types of sinus thrombosis?

The main type of sinus thrombosis is called cerebral venous sinus thrombosis (CVST). CVST can be broken down into different types depending on the venous sinus that is affected. Types include:

• Cavernous sinus thrombosis — Happens when a blood clot blocks the cavernous sinuses behind your eyes.
• Lateral sinus thrombosis — Happens when a blood clot blocks one of the lateral sinuses on either side of your brain.
• Sigmoid sinus thrombosis — Happens when a blood clot blocks the sigmoid sinus in the back of your head and neck.
• Straight sinus thrombosis — Happens when a blood clot blocks the internal cerebral veins.
• Superior sagittal sinus thrombosis — Happens when a blood clot blocks the large vein running along the middle of your brain.

What causes sinus thrombosis?

When a blood clot blocks the veins that drain blood from your brain, it causes increased pressure in your cerebral blood vessels. This increased pressure can cause the blood vessels to swell, or in some cases, burst — causing bleeding (hemorrhage) in your brain. If left untreated, this bleeding can cause stroke, which may lead to brain damage, disability, and death.

What are sinus thrombosis risk factors and complications?

Sinus thrombosis risk factors

Sinus thrombosis is rare in adults. Newborns are at the highest risk for this type of stroke during their first month of life. Risk factors are different for children and adults.

Risk factors for newborns and children include:

• Blood disorders, such as clotting disorders, sickle cell anemia, chronic hemolytic anemia, or beta-thalassemia major.
• Dehydration.
• Head injury.
• Heart disease.
• Infections.
• Iron deficiency.

Risk factors for adults include:

• Blood disorders.
• Cancer.
• Crohn’s disease or ulcerative colitis.
• Infection.
• Obesity.
• Pregnancy, as well as the weeks after giving birth.
• Taking birth control pills.
• Vascular disorders.

Complications of sinus thrombosis

Sinus thrombosis can cause serious complications, including stroke and brain injury. Related complications include problems with speech, movement, and vision, as well as disability and death.

How can I prevent sinus thrombosis?

You may not be able to prevent sinus thrombosis, but living a healthy lifestyle may help to reduce your overall stroke risk. Recommendations to reduce your stroke risk include:

• Control chronic conditions — See a doctor for regular care if you have diabetes or high blood pressure.
• Eat healthy — Eat a healthy diet with lots of fruits and vegetables. They're high in potassium, which promotes healthy blood pressure. Limiting salt from shakers and processed foods also helps reduce your blood pressure.
• Exercise — Aim for at least 30 minutes of moderate-intensity physical activity most days of the week.
• Get preventive care — Routinely check your blood pressure and blood sugar (glucose).
• Manage stress — Take steps to manage stress and get at least 7-8 hours of sleep each night.
• Reduce alcohol intake — Limit alcohol to one drink a day for women and two drinks per day for men.

• Stop smoking — Quit smoking if you smoke cigarettes or marijuana.

How common is sinus thrombosis?

Sinus thrombosis is rare, causing stroke symptoms in about 2-5 out of 1 million people per year.

What Are the Signs and Symptoms of Sinus Thrombosis?

Symptoms of sinus thrombosis may include:

• Coma.
• Fainting or loss of consciousness.
• Headache.
• Seizures.
• Vision problems.
• Weakness or trouble moving part of your body.

When should I see a doctor about my sinus thrombosis symptoms?

If you are having sinus thrombosis or stroke symptoms, dial 911 right away — don’t wait. Getting fast treatment for stroke at the nearest hospital emergency department can reduce your risk of disability and death.

How Do You Diagnose Sinus Thrombosis?

When you arrive at the emergency department, your doctor will perform a physical exam and ask you about any symptoms you are experiencing. 

Tests to diagnose sinus thrombosis

Your doctor will order tests to diagnose sinus thrombosis, which may include:

• Blood tests — Your doctor may order blood test to look for signs of blood clots or other disorders.
• Cerebral angiogram — Uses a small, thin tube called a catheter, x-ray images, and contrast dye to allow your doctor to see the inside of the blood vessels in your brain. This test can sometimes be used to diagnose and treat blood clots.
• CT scan — An imaging test that uses contrast dye to create images of your blood vessels.
• MRI — Uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of your blood vessels.
• Ultrasound — Uses sound waves to create images of your blood vessels.
• Venogram — Uses x-ray imaging and contrast dye to find blood clots in your veins.

Sinus thrombosis prognosis

When sinus thrombosis is diagnosed and treated early, it can reduce the risk of disability and death. New surgical and nonsurgical treatment options have improved survival rates.

How Do You Treat Sinus Thrombosis?

Your doctor may recommend surgery, nonsurgical care, or a combination of both to treat your sinus thrombosis, depending on the location of the blood clot, severity of your symptoms, and your overall health.

Your treatment may include:

Medication for sinus thrombosis

Your doctor may recommend medication to treat sinus thrombosis, including:

• Antibiotics, if your condition is caused by infection.
• Anti-seizure medication, if your blood clot is causing seizures.
• Blood-thinning medications (anticoagulants).
• Clot-busting medications (thrombolytics).
• Water pills (diuretics) to reduce swelling in the brain.

After you are treated for sinus thrombosis, you may need to take blood-thinning medications to reduce your stroke risk. Your doctor will let you know if you need temporary or long-term treatment with blood thinners.

Minimally invasive surgery for sinus thrombosis

Your doctor may recommend a minimally invasive procedure called an endovascular thrombectomy to treat sinus thrombosis. During the procedure, your doctor will:

• Give you local or general anesthesia to keep you comfortable.
• Make a small incision in your upper leg.
• Insert a small, thin tube called a catheter through the incision and into your blood vessel.
• Use x-ray imaging to guide the catheter to the blood clot in your brain.
• Use the catheter to deliver a clot-busting drug directly to the blood clot or remove the blood clot.
• Use x-ray imaging to make sure blood flow is back to normal.
• Remove the catheter and close your incision.

Open surgery for sinus thrombosis

If your condition can’t be treated with minimally invasive surgery and is life-threatening, your doctor may recommend a traditional open thrombectomy procedure to treat your sinus thrombosis. During the procedure, your doctor will:

• Give you general anesthesia.
• Make an incision in your skull to access your blocked vein.
• Remove the blood clot.
• Replace the part of your skull that was removed and close your incision.

Your surgeon may also recommend other procedures, such as a ventricular peritoneal shunt, to help drain excess cerebrospinal fluid, control the pressure in your skull, and reduce the risk of brain injury as you heal.

Why choose UPMC for sinus thrombosis care?

When you choose UPMC for sinus thrombosis care, you will receive:

• Access to world-class neurosurgery expertise —Our world-renowned experts treat the full spectrum of neurosurgical conditions using the latest diagnostic and treatment techniques.
• A full range of treatment options — We offer nonsurgical care, as well as minimally invasive and traditional open surgical procedures, allowing us to effectively treat all types of disorders while reducing your risk of complications.
• Multidisciplinary care — We partner with neurologists, rehabilitation specialists, and other medical experts to provide complete care that optimizes your recovery and quality of life.

By UPMC Editorial Staff. Last reviewed on 2025-02-09.