Identifying Blood Clots

Written By Thomas Hall

What are Blood Clots?

Blood clots in the arteries, blood clots in the veins – There’s no two ways about it – blood clots are bad.

The human body is made up of tissue – muscle tissue, nerve tissue, fat tissue, and tissues that make up the organs of our bodies. These tissues need a constant supply of oxygen in order to stay alive. The tissues of the body get oxygen from arterial blood, blood which has picked up oxygen in the lungs and has been pumped throughout the body by the left ventricle of the heart. Arterial blood first comes out the heart, through the aorta (the biggest artery in our body), and then flows through an ever decreasing caliber of artery until it reaches the smallest, hair-like capillaries of the arterial system. At the capillary level, oxygen is delivered to the tissues of the body. After delivering oxygen, our blood supply crosses over into the capillaries of the venous system and is returned to the heart and lungs, to once again pick up oxygen. And so goes our circulatory system.

For any number of reasons, people can develop blood clots within the circulatory system. If the blood clot is in the venous system, there is a danger that the clot can return to the heart, and be pumped into the lungs where it can cause sudden death. A blood clot that forms on the inner wall of a vein is called a thrombus. If that clot breaks free and travels to the heart, it is called an embolus. If that embolus goes to the lungs, it is called a pulmonary embolus. If an embolus blocks the flow of blood to the lungs, that portion of the lung will die. If many emboli enter the lungs, enough lung tissue can die that the patient dies. Pulmonary embolus is the third most common cause of death from cardiovascular disease behind just heart attack and stroke, and one of the leading causes of preventable hospital deaths.

What Puts You At Risk for Blood Clots?

There are certain conditions that put a patient at risk for the formation of blood clots in the veins of the leg. Recent surgery is one of the leading causes of blood clots in the venous system. Also, prolonged immobility, such as during a prolonged period of bed rest. Even a long trip that causes the patient to be sitting or cramped can predispose the patient to developing a clot in the venous system. Symptoms that may indicate there is a blood clot in the veins of the patient’s leg may include leg pain or swelling, usually in the calf, and clammy or discolored skin. Common symptoms that a blood clot in the veins of the leg has broken free and embolized to the lungs are shortness of breath, chest pain and cough. Anyone experiencing these symptoms should immediately seek medical attention.

Patients can also develop blood clots in their arterial system. These blood clots can also embolize and travel into the smaller arteries of the body, blocking any tissue downstream from the blockage from getting sufficient oxygen. If the oxygen deprivation is bad enough, or persist long enough, the tissue downstream from the blockage will die. For example, if a blood clot clogs an artery supplying blood to the heart muscle, part of the heart muscle can die. Which is known as a heart attack. If a blood clot clogs an artery supplying blood to the brain, part of the brain can die. We call that a stroke. If a blood clot clogs an artery supplying blood to a foot or leg, that foot or leg is jeopardized, and if the condition is not found and treated promptly, the patient may require an amputation.

Symptoms of Blood Clots

The most common first symptom of a blocked artery in the leg or foot is pain.

There are, of course, many causes of pain in the foot and lower leg, such as a pinched nerve, and inflamed tendon or a strained or stretched ligament. In order for a doctor to tell which patients have one of these more benign conditions from those who have a dangerous arterial blood clot, it is vitally important that the physician takes time to ask the patient detailed questions about the pain. Typically, the pain of a patient with a sprain, strain or pinched nerve feels better when the patient is off his/her feet, and is worse when the patient stands and walks. On the other hand, if the patient’s pain seem somewhat better when the patient stands, and feels worse when the patient sits or lies down, this is a red flag for an arterial blood clot. This is because when the patient stands, gravity helps more arterial blood to flow into the lower leg and foot, which supplies more oxygen and eases the pain. Patients with an arterial blood clot will also often describe that they have difficulty sleeping at night, because when they lay down their pain gets worse. Again, when the patient lies down gravity ceases to work in their favor and thus the pain increases.

What to Do When Blood Clots are Suspected

Taking time to ask these important questions of the patient is a fundamental requirement of good medical practice.

Dr. William Osler, one of the founders of Johns Hopkins Hospital and universally regarded as the “Father of Modern Medicine”, famously taught resident physicians “listen to your patient – he is telling you the diagnosis.” When the physician takes time to carefully question the patient about the nature of the pain, and actually listens to the patient’s answers, patients with a probable arterial blood flow can be identified. The physician then performs a physical examination of the patient, paying special attention for the following six signs, known as the “6P’s”: Pain, Pallor, Paresthesia, Paralysis, abnormal Pulses and/or Poikilothermia (fancy word for the extremity feels cool). The doctor does not have to find all 6 of these signs in order to make the correct diagnosis.

The diagnosis is confirmed by objective testing of the patient’s pulses. This testing can be as simple and easy as using a handheld Doppler device, which is actually a handheld ultrasound, that will tell whether there is blood flow in the arteries of the leg and foot, and if that blood flow is normal or diminished. Other more sophisticated tests can then be done to identify the exact locations of the arterial blockages, and its cause. In most cases where the blockage is of sudden onset, the condition is a medical emergency and prompt diagnosis and treatment is of the essence. The longer the condition persists, the greater the chance the patient will suffer an amputation.

The Importance of Testing and Listening

Unfortunately, in our experience at Atlee Hall, some patients with blood clots in either their arteries or veins who seek prompt medical care are misdiagnosed by their medical providers. The majority of instances show that the doctor simply did not take time to ask the right questions, and listen to the patient’s symptoms. This “assembly-line” practice of medicine has become more prevalent in recent years. Tragically, these patients suffer loss of limb or even death that should have been prevented if the doctor had just taken the time to follow the advice of Dr. Osler-– “listen to your patient, he is giving you the diagnosis.”