Blood clots – causes, symptoms & therapy

In addition to the leg and pelvic veins, the heart cavities are also repeatedly affected by the formation of a blood clot. The arteries leading away from the heart can also become blocked with a thrombus.

If such a blockage is present, the doctor does not speak of a thrombus; we’re talking about a heart attack here . Around one in 1,000 people suffers a thrombosis every year . Statistically, women are affected more often than men.

In addition to gender, age and ethnicity also play a major role. Certain risk factors can also favor the formation of a blood clot.

In addition to the usual thrombosis, there is also the so-called traveller’s thrombosis. This occurs mainly after long-haul flights. Even if the risk in a healthy person is just 0.05 percent (that’s about five affected people per 10,000 people), the risk automatically increases if the flight lasts longer than six hours.

causes

A blood clot is mainly caused by damage to the vessel wall, an increased tendency to clot because the composition of the blood has changed, or a slower blood flow. As early as 1856, these causes and factors were identified by Dr. Rudolf Virchow described; for this reason, the three main reasons for a blood clot are also called the Virchow triad.If a venous thrombosis occurs, the causes lie in the increased tendency to coagulate or are due to a slower blood flow. Arterial thrombosis occurs due to damage to the vessel wall. Atherosclerosis is often responsible for such damage.

symptoms and course

Typical symptoms of a blood clot:

• Pains

• feeling of tension

• pressure pain

• calf pain

• dizziness

• inner unrest

The symptoms are relatively atypical at the beginning. The patient complains of stress-related pain that occurs spontaneously and improves after the affected part of the body (e.g. the leg) is elevated. Furthermore, those affected report a feeling of tension or the pain is often equated with sore muscles. Other symptoms are pressure pain on the sole of the foot, calf pain when moving or bending the foot or when pressure is applied.

The affected leg also feels warmer. The symptoms can, but do not always have to, occur. The signs vary from person to person. If a pulmonary embolism occurs as a result of the blood clot, the main symptoms to be seen are those that make breathing difficult or the patient also suffers from anxiety , restlessness and dizziness. If the blood clot forms in the arm, the patient complains of severe pain; veins can often even be seen on the surface of the arm.

The greatest danger is the development of an embolism. The blood clot breaks loose, is absorbed into the blood, and can travel to either the lungs or a vein in the heart. Other life-threatening complications occur when bacteria that cause blood poisoning are already present . With timely treatment, complications rarely occur; the prognosis of a blood clot is positive.

Diagnose

The doctor can use imaging methods – such as an ultrasound – to make the diagnosis. Since the therapy depends on how long the blood clot has existed, it is important that it is diagnosed relatively quickly. It is also possible for the D-dimers in the blood to be determined so that the doctor can rule out a possible blood clot. However, ultrasound examinations are used as standard methods; above all, compression sonography or Doppler sonography is used here. In addition to the ultrasound, an X-ray examination in conjunction with a contrast medium can also provide information about whether a blood clot is present.

complications

Blood clots can cause various complications. Embolism is one of the most serious consequences . An embolism occurs when the blood clot breaks loose and travels through the bloodstream to other parts of the body. There is a risk that it will clog an important vessel. If the clot is transported to the lungs via veins and the right heart, there is a risk of a pulmonary embolism.

Pulmonary embolism is a complication of deep vein thrombosis in the leg and occurs in every second patient. The degrees of severity can vary. In the worst case, the pulmonary embolism can even be fatal.

Another life-threatening complication of the blood clot is blood poisoning (sepsis). The clot is colonized by bacteria that spread throughout the body via the bloodstream. In such cases, treatment with antibiotics should be given.

Also one of the possible effects of a blood clot is the postthrombotic syndrome, which is manifested by chronic venous insufficiency. This is a permanent weakness of the veins, which is associated with varicose veins, edema (water retention), inflammation of the skin and the formation of ulcers. The varicose veins form when the blood vessels become occluded. As a result, bypass routes are created via the superficial veins. Permanent obstruction of blood flow leads to a leg ulcer that usually takes a long time to heal. Complications such as bleeding, wound healing disorders, sensory disorders and nerve paralysis also threaten when blood clots are surgically removed.

treatment and therapy

The primary aim of the therapy is for the doctor to try to dissolve the blood clot so that the blood flow can be restored properly. Treatment is called thrombolysis and depends on how old the clot is. The patient is given heparin , which ensures that blood flow is restored. Since heparin inhibits blood clotting, the clot can be dissolved.

The patient should also raise their legs or apply a compression bandage. In rare cases, surgical measures are also used. The doctor surgically removes the blood clot, including open thrombectomy, balloon catheter, and compression thrombectomy. In open thrombectomy, the blood clot is removed; however, this method is only possible when a very short section is affected by the clot. With the balloon catheter, a catheter is inserted which is connected to an inflatable balloon.

The physician directs the catheter past the clot, inflating the balloon and advancing the clot to the site of the rupture for easy removal. In compression thrombectomy, pressure is applied to the vein in an attempt to “squeeze” the blood clot out. Furthermore, follow-up examinations are important so that the doctor can check whether the treatment is effective or whether the surgical method was successful.

prevention

A blood clot can be prevented by regular exercise as well as by drinking enough fluids. It is also important that support stockings are worn after operations of any kind. Standing or sitting for a long time, nicotine , being overweight and alcohol also promote a blood clot.

In this context, the birth control pill can also significantly increase the risk of a blood clot, especially if other risk factors (obesity, smoking) are present. Before long-haul flights, it is advisable to take blood- thinning medication .