Circulatory Disorders (Arterial Circulatory Disorder, PAD): Causes, Symptoms, and Treatment of Narrowed Blood Vessels

Medical professionals distinguish between:

• arterial and venous, and
• acute and chronic circulatory disorders

Arteries are blood vessels that pump oxygen-rich blood from the heart throughout the body.

Veins, on the other hand, carry the blood back to the heart after it has delivered its oxygen.

An arterial circulatory disorder (also known as peripheral arterial disease) occurs when an artery is narrowed or even completely blocked. 

This can affect peripheral arteries (such as those in the legs) or central arteries that supply organs (such as the coronary arteries, renal arteries, and intestinal arteries).

If the blockage or narrowing occurs in a vein, doctors refer to it as a venous circulatory disorder.

These include, for example:

• deep vein thrombosis and
• varicose veins

During a heart attack, heart muscle tissue dies, causing the heart to no longer function properly © Henrie | AdobeStock

An acute circulatory disorder occurs when symptoms arise due to a sudden blockage of a blood vessel. Depending on the affected organ, an acute blockage can constitute a medical emergency. In such cases, immediate emergency medical intervention is required.

Such emergencies include, for example:

• a pulmonary embolism
• a heart attack, or
• a stroke

A chronic circulatory disorder usually develops over a longer period of time. Depending on the affected area of the body, various symptoms may occur.

An acute circulatory disorder is caused by a blockage in a blood vessel due to:

• a thrombus or
• an embolus

A thrombus is a blood clot in a blood vessel—that is, a small clump of blood that can block the vessel.

An embolus occurs when a thrombus breaks loose and blocks the blood vessel again at a different location.

A blockage caused by a thrombus is called a thrombosis. A blockage caused by an embolus is called an embolism.

A blood clot can form in the following cases:

• after vascular injuries and surgeries
• in cases of blood clotting disorders
• when blood flow is significantly slowed or spontaneously

A chronic circulatory disorder is usually caused by narrowing (stenosis) of a blood vessel; less commonly, it is caused by a blockage.

Vascular narrowing can occur if the vessel is kinked or if something is pressing on it from the outside.

Other causes of chronic circulatory disorders include:

• Vascular inflammation (phlebitis)
• Trauma (injuries) or
• genetic vascular changes

In most cases, atherosclerosis (commonly known as hardening of the arteries) is responsible for the development of narrowings.

In atherosclerosis, the inner walls of the arteries are covered with cholesterol deposits (plaques). These deposits grow over the years and can thereby impair blood flow.

Fewer and fewer blood cells can then pass through the narrowed area. Blood clots can also become lodged here, leading to an acute vascular occlusion.

Illustration of a narrowed blood vessel due to atherosclerosis © peterschreiber.media | AdobeStock

In cases of chronic arterial circulatory disorders, new blood vessels may form to bypass the narrowed area. These vessels thus ensure an adequate supply of oxygen and nutrients for a certain period of time.

Depending on where the blockage or narrowing occurs, different clinical presentations may result:

• Coronary heart disease (narrowing of a coronary artery)
• Heart attack (blockage of a coronary artery)
• Stroke (vascular occlusion in the brain)
• Pulmonary embolism (blockage of a blood vessel in the lung)

In principle, any blood vessel or organ can be affected by narrowing or blockage.

In peripheral arterial disease (PAD) (colloquially known as “intermittent claudication”), the peripheral blood vessels—usually in the legs—are narrowed or blocked. PAD can therefore be chronic or acute.

Circulatory disorders in the legs or feet typically manifest as pain when walking or climbing stairs. As the condition progresses, symptoms may occur even at rest. Medical professionals distinguish between acute circulatory disorders, which arise suddenly due to a vascular occlusion, and chronic forms, which develop over the course of years. Narrowing in the arteries of the carotid artery or the brain is particularly dangerous, as it can trigger strokes.

Risk Factors for Atherosclerosis

The most important risk factors for atherosclerosis—the primary cause of circulatory disorders—include:

• Overweight and obesity
• Smoking
• High blood pressure
• High cholesterol
• Diabetes
• Poor diet (too much fat, meat)
• Insufficient physical activity
• Lipid metabolism disorders
• Advanced age
• Genetic predisposition
• Risk factors for thrombus formation

Other risk factors for the formation of a thrombus (embolus) include, for example:

• Blood clotting disorders
• Cancer
• Cardiovascular disease (such as heart failure)
• Obesity
• Bedridden status
• Immobilization of a limb
• Surgeries and injuries
• Pregnancy and the postpartum period
• Nephrotic syndrome (kidney disease)
• Severe varicose veins
• Smoking
• Use of the birth control pill
• Hormone replacement therapy during menopause
• Taking certain medications, such as cancer drugs
• Advanced age (over 60)

Sweet and fatty foods, especially when consumed in excess, are a risk factor for circulatory disorders © happy_lark | AdobeStock

The nature of the symptoms depends on various factors, such as:

• Does the narrowing occur in only one place or in multiple places within the blood vessel?
• How severely is the blood vessel narrowed?
• Is the condition acute or chronic, and is it a venous or arterial circulatory disorder?
• Which blood vessel or body region is affected?

Acute occlusion in the extremities

An acute vascular occlusion in the extremities causes:

• cold feet or hands
• Numbness
• pain and
• marbled white skin

There is no pulse in the affected areas. Any wounds will no longer heal. If internal organs such as the intestines are affected, this leads to an intestinal infarction with very severe abdominal pain. In extreme cases, this can result in intestinal paralysis.

In Raynaud’s syndrome, a harmless circulatory disorder, the toes and fingers experience a brief lack of blood flow. They first turn white and then bluish, but blood flow resumes after a short time.

Raynaud’s syndrome

If the patient suffers from peripheral arterial occlusive disease, blood flow to the legs is usually impaired.

Because the muscles are not receiving enough blood, the patient experiences pain and must stop and rest at regular intervals (“intermittent claudication”). In a later stage of the disease, severe tissue damage—including “smoker’s leg”—can result.

Other Symptoms

If the heart is affected by chronic circulatory disorders, the patient develops coronary heart disease (CHD). This manifests as chest pain of varying severity and, in the worst case, as a heart attack.

Phlebitis affects only the legs. They become swollen, feel hot to the touch, and are tender to pressure. Redness of the skin appears at the affected sites.

The pain associated with phlebitis can be relieved by elevating the legs. Unlike with arterial circulatory disorders, the pulse in the legs is still detectable in cases of phlebitis.

Chronic circulatory disorders should also be managed by an experienced medical professional. If you have one or more symptoms, you should promptly consult a specialist in angiology (a specialist in vascular diseases).

After completing the preliminary examinations, the specialist verifies their suspected diagnosis using various methods.

A blood test provides information on blood lipid and blood sugar levels and is used to determine coagulation factors. This allows the specialist to identify which risk factors are significant for the patient.

If blood pressure measurements on both arms or legs yield different values, this indicates unilateral narrowing of the blood vessels.

The Physical Examination

By calculating the ankle-brachial index (ABI, Doppler index), the doctor can detect circulatory disorders in the leg.

To calculate it, the blood pressure reading taken at the patient’s ankle is divided by the reading taken at the upper arm. Values less than or equal to 0.92 indicate peripheral arterial disease.

Various other physical tests can also provide evidence of circulatory disorders.

These include, for example:

• the Allen test (fist-clenching exercises)
• the Ratschow positioning test (circular movements of the feet) or
• the walking test to determine the pain-free distance.

In the first two tests, the doctor looks for skin discoloration (redness, paleness). In the walking test, however, the doctor observes whether and when pain occurs in the legs.

Conclusions about tissue perfusion can be drawn indirectly using transcutaneous oxygen partial pressure measurement. In this procedure, sensors on the skin measure the oxygen content in the tissue.

Imaging Diagnostics

Various imaging techniques can be used. A specialized ultrasound device determines the flow velocity and direction of blood within the arteries (Doppler and duplex sonography).

Computed tomographic angiography (CTA) provides excellent visualization of the blood vessels.

The following methods are available as alternatives or for specific diagnostic questions:

• radiation-free magnetic resonance angiography (MRA),
• digital subtraction angiography (DSA), and
• conventional angiography (a type of X-ray examination)

The latter is also frequently used in the context of vascular surgery. These procedures can be used to identify narrowed areas in the blood vessels. By administering a contrast agent, the doctor can visualize the blood vessels and the narrowings even more precisely.

Angiography can visualize blood vessels © Ploypilin | AdobeStock

Treatment for circulatory disorders is:

• symptomatically (based on the symptoms present) or
• causally (based on the underlying cause).

Specialists in circulatory disorders include:

• Angiologists
• phlebologists
• Vascular surgeons and 
• Cardiologists (when coronary arteries are involved)

Varicose veins are a common form of circulatory disorder in the legs © zlikovec | AdobeStock

An acute vascular occlusion is often a medical emergency. It requires immediate surgical intervention to restore blood flow through the vessel (revascularization).

Intensive care is also required in such cases. The same may sometimes be true for chronic vascular diseases.

A blood clot can be surgically removed to reopen the vessel.

During a thrombendarterectomy, doctors remove not only the blood clot but also atherosclerotic changes in the vessel wall (endarterectomy).

To widen a narrowed blood vessel, the vascular surgeon uses balloon catheters or stents (wire scaffolds), which may be drug-coated.

By placing a vascular bypass, they bypass the blocked section of the vessel. A vascular bypass is a type of vascular implant.

To dissolve a thrombus (lysis treatment), doctors inject various substances (fibrinolytics), such as:

• streptokinase
• Urokinase and
• Plasminogen activator (rt-PA, alteplase)

In certain cases, the patient is also given heparin.

In cases of very severe circulatory disorders and prolonged insufficient blood supply, tissue necrosis occurs. This then makes amputation of the affected body part necessary.

The following medications are used for drug therapy or to prevent thrombosis:

• vasodilators (prostaglandins) or
• anticoagulants (antiplatelet agents such as acetylsalicylic acid, ASA, or clopidogrel)

If the patient is in pain, the doctor prescribes pain relievers or, in severe cases, administers morphine via injection.

In cases of chronic peripheral arterial disease (PAD), specially supervised walking and vascular training, as well as moderate physical activities (swimming, cycling), can be helpful.

This can improve the oxygen supply to the affected part of the body. Warm arm baths increase blood flow.

As part of causal therapy and to prevent the condition from worsening, the doctor recommends eliminating the risk factors:

• Lower blood pressure in cases of hypertension
• Smokers should quit smoking
• Overweight individuals should follow a calorie-restricted diet

Diabetics should maintain good blood sugar control; the doctor should monitor blood lipid levels and cholesterol levels and adjust medication as needed.

How can circulatory disorders be recognized?
Circulatory disorders can often be recognized by typical symptoms: cold hands or feet, pale skin, pain when walking or climbing stairs, and poor wound healing on the legs or feet. If pain occurs even at rest, this indicates an advanced stage of the condition. A doctor can confirm the diagnosis using an ultrasound or a blood flow test.

What is the most common cause of circulatory disorders?
The most common cause of circulatory disorders is atherosclerosis—that is, plaque buildup in the arteries that causes narrowing of the blood vessels. This impedes blood flow, and the affected limbs or organs receive insufficient oxygen. This vascular disease particularly often affects the legs, the heart, and the carotid artery.

What types of circulatory disorders are there?
Medically, a distinction is made between arterial and venous circulatory disorders. Arterial circulatory disorders result from narrowed or blocked arteries, while venous circulatory disorders impair the return of blood to the heart. Acute circulatory disorders occur suddenly and can be caused, for example, by a blockage in a cerebral artery. Chronic forms develop slowly and often lead to permanent narrowing.

What are the potential consequences of circulatory disorders?
The consequences of circulatory disorders range from exertion-induced pain and numbness to tissue damage. In severe cases, restricted blood flow can lead to amputation. The legs or feet are often affected, but so are the heart and the brain. If left untreated, a heart attack or stroke can occur when a blocked blood vessel affects vital organs.

How can circulatory disorders be prevented?
To prevent circulatory disorders, risk factors such as smoking, being overweight, and a lack of physical activity should be avoided. Regular physical activity, a balanced diet, and managing high blood pressure and blood sugar significantly reduce the risk. Targeted walking exercises also promote blood circulation in the legs. Since cold or stress can further constrict blood vessels, it is advisable to wear warm clothing and prioritize relaxation. In addition to exercise and a healthy diet, it helps to avoid cold and stress, as both constrict blood vessels and affect blood pressure. This can have a positive long-term impact on the course of circulatory disorders.

How do circulatory disorders progress, and when should you seek medical attention?
The course of the disease in cases of circulatory disorders depends on the cause and the affected blood vessel. Initially, symptoms occur only when walking or climbing stairs; later, they may also occur at rest. Medical intervention is always necessary if pain, cold extremities, or non-healing wounds on the feet or legs occur. Early treatment can prevent the disease from progressing and avoid complications.

The course of circulatory disorders also depends on the cause and the type of blood vessel affected. Arteries and veins react differently to deposits in the arteries that restrict blood flow. The course of the disease is usually monitored using imaging techniques to detect narrowings at an early stage. Among the most common circulatory disorders are peripheral arterial disease (PAD), coronary artery disease, and cerebrovascular disease. Their consequences range from chest pain to heart attack to the occlusion of a cerebral artery.