Symptoms of Blood Clotting

Vital for the healing of wounds, a blood clot is a semi-solid accumulation of sticky blood cells and fibrin strands that forms if a blood vessel is damaged. The clot is meant to seal the damaged blood vessel, keeping blood from leaking out. Once the vessel heals, the blood clot should dissolve. However, a blood clot may block the flow of blood through a vein or artery. Obstructed blood flow can lead to potentially fatal complications, including heart attack or stroke. Blood clots can be divided into categories. A thrombus is a blood clot in the heart or attached to the inner wall of a blood vessel. An embolus clot does not remain in the vessel where it forms but moves through the bloodstream. When an embolus clot arrives at a blood vessel too small to pass through, it becomes stuck, causing sudden, severe complications. The specific symptoms or effects of blood clots depend on where they become lodged.

Arterial Blood Clots

• A blood clot that obstructs the flow of oxygenated blood through an artery can cause serious organ and tissue damage. These clots can have dire consequences, depending on where they are. For example, a clot formed in the eye can cause irreversible blindness. Insufficient blood flow means the area is deprived of oxygen (called ischemia). Pain is generally the first symptom, but loss of function of the affected area can ultimately result.

Arterial Clots in the Brain

• Clots blocking the blood flow, and in turn the oxygen supply, to the brain cause strokes. Symptoms of this type of clot are usually more acute on the opposite side of the body. For this reason, loss of sensation or even paralysis in one side of the face, a leg or an arm may occur. Speech impairment is a likely result if the clot is on the left side of the brain. Other symptoms include weakness, headaches, visual disturbances and confusion.

Arterial Clots in the Heart

• Clots obstructing blood flow to the heart often result in heart attack, as the part of the heart that lacks oxygen can die. The first symptom is pain that begins in the chest and travels to the arms, back and jaw. Irregular heartbeat, increased pulse and tightness in the chest further warn of a heart attack. Other symptoms include shortness of breath, nausea, vomiting and fainting.

Arterial Clots in the Abdomen

• Blood clots in the abdomen will be accompanied by intense abdominal pain, diarrhea and vomiting. If an area of the bowel is deprived of oxygen, diarrhea may be bloody.

Arterial Clots in the Lungs

• Known as a pulmonary embolism, a blood clot can block the pulmonary artery in the lungs. If the embolus is small, shortness of breath will likely be the only sign. Symptoms of pulmonary embolism tend to appear suddenly and often resemble a panic attack, with rapid breathing and general restlessness in addition to fainting or lightheadedness. Trying to take a deep breath may result in sharp chest pain. Someone with pulmonary infarction, when lung tissue has begun to die, will probably have a fever, experience severe chest pain and cough up blood. Symptoms of pulmonary infarction come on more slowly than those of pulmonary emboli, appearing over the course of a few hours to a few days.

Arterial Clots in the Limbs

• As with other arterial blood clots, sudden pain and tenderness is the first sign of a blood clot in a leg or arm. This pain may be localized, just over a vein. A dull throbbing may also occur. The limb may become warm and swollen, and take on a bluish-white hue. Weakness, loss of sensation or paralysis are also possible.

Venous Blood Clots

• Venous clots prevent blood from returning to the heart. These most commonly occur in the limbs and cause pain, swelling, warmth and redness. When blood clots are formed deeper in the veins (typically in the legs), called deep vein thrombosis, they are more dangerous because they can become emboli and move to the heart or lungs. Surface veins may become inflamed if they are obstructed by a blood clot. This may produce pain, but they are unlikely to become emboli and cause serious complications in other organs.