These symptoms will help you identify a blood clot in your head


A blood clot is known in medicine as a "thrombus" and can form either in a vein or in an artery. A blood clot consists of blood platelets (thrombocytes), connective tissue components and deposited blood lipids. In an artery, a blood clot usually results from damage to the vascular wall, e.g. is the case with high blood pressure. If the blood clot forms in a vein, the reason is usually a greater tendency to clot or changed flow properties within the blood vessel. A blood clot in the head clogs the affected vessel and disrupts the blood supply to the brain, causing a stroke, which is medically correctly referred to as "ischemic stroke" or "ischemic insult".


These are the main symptoms of a blood clot in the head or a stroke. The most important features are explained in more detail below.

  • Hemiplegia with a focus on one arm / leg
  • Sudden language disorder
  • Sensory disturbances on the affected side of the body
  • Disturbances in perception of one side of the body and the surroundings of this side. The patient virtually "forgets" that this page exists
  • Visual disturbances
  • dizziness
  • Eye rotation to the affected side of the brain (focus view)
  • a headache
  • Swallowing disorder
  • Loss of consciousness
  • Breathing disorder

a headache

Headache can be an accompanying symptom of a blood clot in the head. About a quarter of patients who suffer a stroke caused by a blood clot in one of the arteries supplying the brain experience severe headaches shortly before or with the onset of the rest of the stroke symptoms. But also a blood clot in the venous system of the brain, the so-called sinus veins, can cause headaches. Such a blood clot is called a sinus vein thrombosis, which leads to a build-up of blood and nerve fluid in the head. This congestion causes swelling of the brain, which causes headaches. Other symptoms of sinus vein thrombosis are visual disturbances, swelling of the face, epileptic seizures and psychological changes.

Read more about the different types and causes of headaches.

Difficulty speaking

Difficulties with language are divided into different groups in medicine. There is motor aphasia (Broca's aphasia), which describes a problem with speaking. Patients understand what they are being told but may have difficulty finding words. With this type of language difficulty, the center in the brain that controls language production (Broca's area) is damaged. The patient therefore speaks hard in very short sentences.

The second category includes the so-called sensory aphasia (Wernicke aphasia). The opposite is true here: the speech muscles work perfectly, but the center in the brain that is responsible for understanding speech (Wernicke area) does not work. In most patients, both Broca's and Wernicke's areas are located in the left hemisphere and can be cut off from the blood supply by a blood clot in the head and be damaged by the insufficient oxygen supply. Another consequence of a blood clot in the head can be paralysis of the speech muscles without affecting the two centers for speech understanding and speech production. It is important to note that patients who suffer from a speech disorder due to a blood clot in their head have problems with the production and understanding of language, but they are not mentally disabled.


Nausea and vomiting, along with other symptoms typical of a stroke, may indicate a blood clot in the head (or bleeding in the brain). Possible mechanisms are the increased intracranial pressure, which can cause sudden nausea and vomiting. If the brain stem is damaged by a blood clot in the head, vomiting can occur because this is where the vomiting center is located. Nausea and vomiting can also occur as a result of the dizziness during and after a stroke from a blood clot in the head.


Sudden dizziness can be the symptom of a blood clot in the head. With this type of stroke, the parts of the brain that are responsible for balance are no longer supplied with blood. This vertigo can feel as if the room is spinning (vertigo) or as if the floor is shaking under your feet (vertigo). Another form of dizziness is the feeling of going down in the elevator. These vertigo attacks usually occur with an unsteady gait pattern.

You might also be interested in this topic: Dizziness after a stroke.


In medicine, convulsions are divided into generalized seizures that affect the whole body and focal seizures that only affect one area of ​​the body. With generalized convulsions, the patient is unconscious, with focal convulsions, he or she usually does not lose consciousness. Brain spasms are caused by dysfunction of the brain cells. If there is a blood clot in the head, blood flow to the nerve cells is impaired. Occasionally, cramps can then result.


If the blood supply to the parts of the brain is interrupted by the blood clot in the head, paralysis occurs. If the middle cerebral artery is blocked, hemiplegia occurs, which affects the arm and face most severely. If the anterior cerebral artery (A. cerebri anterior) is affected, the leg is most affected. If smaller vessels in the terminal area of ​​the deep perforating arteries (connections between superficial and deep cerebral vessels) are closed, paralysis on one side of the body can also vary in severity.

Further information on this topic can be found on this page: Symptoms of paralysis on the leg

Visual impairment

Visual disturbances caused by a blood clot in the head can occur when blood vessels that supply blood to either the eye, the optic nerves, or the visual cortex (the area of ​​the brain responsible for vision) become blocked. Specifically, these are the ophthalmic artery (supplies the eye) and the posterior cerebral artery (posterior cerebral artery). If there is a blood clot in the ophthalmic artery, one eye is completely blind. If there is a blood clot in the posterior cerebral artery in the part that supplies the visual pathway (nerve fibers from the optic nerve to the visual cortex), homonymous hemianopsia occurs: either the right or the left part of the visual field becomes blind in both eyes. If the part that supplies the visual cortex is affected, the patient can become completely blind. Another possible visual disorder caused by a blood clot in the head is double vision.

You may also be interested in this topic: Dizziness and blurred vision


"Tinnitus" describes a noise in the ear that only the affected patient hears. Tinnitus can occur on only one side or on both sides. These noises are perceived as humming, whistling or hissing. The exact cause of tinnitus has not yet been clarified Circulatory disorders caused by small blood clots in the vessels that supply the hair cells (these are the names of the nerve cells in the ear) are discussed as a possible cause of tinnitus.

Read more on the topic here Tinnitus.


Hiccups are one of the possible symptoms of a blood clot in the head. However, it is never the only symptom of a blood clot or stroke. Only when other symptoms such as sudden paralysis, speech disorders, headaches etc. occur at the same time, the hiccups should be considered a symptom of a blood clot. Usually, hiccups are harmless and will stop on their own after a short time.

Mental changes

Many psychological processes are controlled in the frontal lobe. If its blood supply is interrupted, a blood clot in the head can lead to changes in the psyche. Occlusion of the anterior cerebral artery (anterior cerebral artery) can disrupt a patient's internal drive. If the posterior cerebral artery is occluded, psychological changes can also occur. In general, a blood clot in the head can disrupt consciousness and reduce the patient's perception.

You can find more information on this subject here: Passed out and Mental disorders