Blood clots can be described as semi-solid, viscous masses made up of blood cells. They form when blood vessels are damaged. They are used to prevent bleeding and seal any leaks. A clot can block an artery (or the thrombus) and prevent blood flow to an organ. This can lead to tissue damage. An infarction. An infarction is a blood clot that breaks away (embolism), from the area it was meant to protect.

Heart Attacks

Most strokes and heart attacks are caused by blood clots. They can also cause damage to other organs. A blood clot (thrombus), forms in at most one of the arteries that supply blood blood to the heart. It blocks blood flow to a part of the heart muscle. This decreases or stops oxygenation. The affected heart muscle will die and then a heart attack is possible.

  • Stroke is caused by clots that block oxygen from the brain.
  • Sudden blindness can be caused by clots in the eye.


A thrombosis is a blood clot that causes an obstruction. Almost always, thrombosis in veins is associated with phlebitis, which is inflammation of the vein. Thrombophlebitis refers to inflammation of the vein where the blood clot formed.

Thrombophlebitis can be classified as either superficial or deep. The thrombosis that causes the thrombophlebitis may occur in either a superficial (on the surface) vein or a deeper (below).

When blood clots in a vein close to the surface of the skin (superficial thrombophlebitis) it is called a superficial vein.

Deep vein thrombosis is when blood clots in a deeper vein such as the veins of the lower leg and thigh. DVT is more serious than superficial thrombophlebitis. If they travel to the lungs, these clots may break off (embolise), from a blood vessel. For more information about pulmonary embolisms see the section ‘Symptoms and complications. People over 40 are more likely to experience deep vein thrombosis.


The following are the causes of blood clots:

  • A disruption in blood flow due to obstruction
  • A blood vessel injury
  • A change in blood composition (e.g. Too many clotting factors in blood)
  • A blood clot in the blood vessels that carry blood to the brain can cause an Ischaemic Stroke. This is caused by blood clots that have formed in the heart from rhythm disorders such as atrial fibrillation or atrial flutter.


Atrial fibrillation refers to an irregular heartbeat, also known as an arrhythmia. It is characterized by rapid, quivering beats occurring in the atrium (upper chamber) of the heart. The irregular pumping may cause blood to pool and form clots which can then reach the brain. An embolus may also develop after a heart attack or valve disease, as well as on artificial heart valves.

Cardiogenic embolism is a condition where a clot forms in the heart, then moves to the brain. If a person has suffered a heart attack, a stroke could occur. A heart attack can cause damage to the heart, causing it to stop pumping blood properly. This can lead to clots that migrate to the brain. Clot-making agents such as artificial heart valves can also be found in them. Anticoagulant medications are often prescribed to people with artificial heart valves in order to prevent the formation of clots.

An atherosclerosis-related narrowing of an artery can lead to blood clots. This phenomenon is commonly called hardening the arteries. Atherosclerosis can cause the walls of the artery to harden over time. The artery then narrows until there is less blood flow. These arteries are vulnerable to injury. They can also tear and form clots, which will block the already narrowed artery, interrupting oxygen supply to the brain or heart.


Clots can also form from blood clotting disorders or rare blood disorders, although the reason is not always clear.

Some women may experience increased risk from blood clots by taking an oral contraceptive (birthcontrol pill). Women over 35 who smoke, or have had a bloodclot, are at greater risk.

Inflammation of the superficial vein can occur for many reasons. Trauma or injury are common causes of inflammation of a superficial vein. In hospital, into a vein. Infection can result from puncturing the vein in order to administer the medication or solution. A trauma to the vein, such as a car accident injury, can cause inflammation, which can lead to pain, redness, and swelling. This causes an increase in blood flow to injured areas and can lead to clot formation. Although it is unpleasant, superficial thrombophlebitis rarely causes any serious complications.

Sometimes, thrombophlebitis can be caused by a bacterial infection in the vein. A bacterium known as staphylococcus is the most common pathogen. This micro-organism is often found on the skin.

Sometimes, thrombophlebitis can occur without any obvious cause. It can happen in the leg vein of pregnant women, people with varicose or some people who have abdominal cancer (especially pancreatic) and people with varicose. Women over 35 years old who smoke or take oral contraceptives (birth Control pills) are at greater risk for blood clots.

Dyb venetrombose

It is when blood clots form in a deep vein. DVT can often be caused by:

  • Longer sitting, or resting in bed
  • Surgery or trauma (especially hip or gynaecological, or heart surgery)
  • Medicines such as contraceptive pills and medicines containing high levels oestrogen are known to be dangerous.
  • Injury to the leg, or immobilization due to a cast that has been used to treat fractures
  • Hospitalization (currently or within the past 3 months)
  • Treatment for cancer
  • infektion

Deep vein thrombosis is more common in people with certain hereditary conditions. Blood flows through the veins based on how they contract. If blood is not contracted, such as during prolonged bed rest or inactivity, it can accumulate in certain areas and cause clots.

Symptoms and Complications

Angina (chest pain) can be caused by blood clots. These usually start in the middle of the chest, then move to the jaw, back and sometimes the left arm. However, pain can also be felt in your stomach. This is less common.

Although heart attacks are usually very painful, they can also be quite mild. Some people experience’silent heart attacks’, which are not accompanied by any symptoms. Some people feel like they are dying when a heart attack happens. The heartbeat is often very fast and they feel tight in their chests. Your heart might beat faster or irregularly. You may experience shortness of breath, difficulty breathing, nausea, vomiting, fainting, or even collapse.

Women and men may experience different symptoms from a heart attack. Women tend to feel more nauseated and sweat less. Women may also feel less pain in the chest and it can extend to the neck, jaw, and back more often than men.

Clots can cause strokes that affect the opposite side of your body from their location in your brain. This can cause loss of feeling on one side or all of the body. A speech impairment may occur if the left side is affected. This could result in the person being unable to understand or speak the words they hear. You may also experience confusion, blurred vision or severe headaches.

Even if the symptoms seem minor or insignificant, stroke signs should be treated seriously. Even if symptoms subside within a few minutes it is crucial to get medical attention right away.

Although it can cause pain and discomfort, inflammation in a superficial vein (or surface) – such as the veins of the arm into the catheter or blood draw – is usually not considered to be serious. It is uncommon for blood clots in superficial veins to rupture and carry blood. This can cause blockage (thromboembolism), and complications in other organs, such as the lungs.

DVT Symptoms

Deep vein thrombosis can lead to pain, swelling, redness, heat, and redness in the legs. Standing may cause pain in the leg. This condition typically affects one leg. Deep vein thrombophlebitis is a condition that affects only one leg. Many people with deep vein thrombophlebitis don’t show any symptoms.

  • Tissue swelling and hardening
  • Pain or tenderness in the vein area
  • When the foot is bent upwards, it causes sharp pain.
  • Rødme
  • A feeling of warmth in the affected region.
  • A dull, sharp pain in the calf when you walk, especially if it isn’t moving
  • Dilatation (enlargement), of the superficial legs veins

Deep vein thrombosis may lead to serious complications. An embolus is a blood clot which has formed in a deeper, larger vein. This can happen in veins in the legs, abdomen, or pelvis. Travel through the vein. The embolus can lodge in the lungs and cause pulmonary embolism.

A clot in deep veins does not always cause symptoms. The first sign of a clot is usually when it has entered the lung. Shortness of breath, chest pain, and bloody sputum are all signs of pulmonary embolism (embolism within the lung). If you have any of these symptoms, it is important to seek medical attention immediately.


There are several tests that can be done to determine if there is a blood clot.

  • Computed Tomography (CT), a specialized technique that uses an X-ray machine to combine multiple X-ray images into a detailed image of a specific part of the body. This image is 100 times more clear than an ordinary Xray.
  • Magnetic resonance imaging (MRI)
  • Ultrasound of veins in the leg and arteries in head and neck
  • Angiography and Phlebography
  • Echocardiography (ultrasounding the heart);
  • Electrocardiography (ECG).

A recent heart attack may be detected by blood tests. You may need to have blood tests done if you have a history of thrombophilia, are younger than 40, or have had repeated blood clots. This is a condition where blood clots abnormally and increases the chance of getting clots.

The symptoms of superficial thrombophlebitis are usually what diagnose it. A doctor will examine the patient and ask about their medical history.

To confirm the diagnosis of thrombophlebitis (thrombophlebitis), an ultrasound may be performed to examine the veins. Deep vein thrombosis pain is similar to muscle pain so the doctor might look for signs of swelling or bruising in the calf due to dilation of the vein.

A compression ultrasound is used to confirm the diagnosis of deep vein embolism. The test can detect differences in the sounds or echoes made by blood and detects a blood clot in deep veins.

Treatment and Prevention

Medication is often prescribed to stop DVT from progressing and to prevent blood clots from migrating to the lungs. You should seek immediate medical attention if you suspect you may have deep vein thrombosis.

Each person’s medical history, preferences, health issues, cost, and convenience of treatment will all play a role in the choice of anticoagulant. After the blood clot is diagnosed, the medication can be continued for many months. There are many factors that affect the length of treatment, such as whether it is a first or recurrence episode, the specific cause of the episode, and whether there are any other health issues (e.g. Active cancer). The majority of people don’t need to be admitted for treatment. People with deep vein thrombosis usually return to their daily activities in 2 to 3 weeks.

Some people may need long-term anticoagulant treatment or oral anticoagulants To prevent deep vein thrombosis, the doctor may recommend elastic support stockings. To relieve pain, painkillers can be used.

Mild inflammation and discomfort can be relieved by elevating the area. Warm, moist compresses can be used for 15-20 minutes at different times throughout the day to ease the pain. Walking is a good option for superficial thrombophlebitis. If symptoms and inflammation last more than two days or worsens, it is important to consult a doctor as soon as possible.

In cases of thrombophlebitis due to an infection, antibiotics may be used to treat it. Rarely, if antibiotics fail to control the infection or the symptoms worsen, surgery may be necessary to remove the affected vein.

It is recommended that you avoid prolonged periods of immobility (e.g. during long flights or car rides) and that you walk for at least 30 minutes each hour. If possible, elevate your legs above the heart. For those with a blood clot in their legs, compression stockings are recommended.


Avoiding blood clots can help you avoid stroke and heart disease. You should quit smoking or control your blood pressure. High cholesterol can also be a risk factor. This can be managed medically. A healthy diet and regular exercise can help reduce your risk of a stroke or heart attack.

For more information, see our articles on stroke and heart attack.