Understanding Peripheral Artery Disease

Peripheral Artery Disease (PAD) is a chronic condition caused by atherosclerosis that leads to insufficient blood supply to the limbs. Its early symptoms may be subtle, but as the disease progresses, it gradually affects daily life. Understanding the characteristic symptoms aids in early diagnosis and treatment, preventing severe complications. This article will detail the symptoms at different stages, the progression pattern of symptoms, and when immediate medical attention is necessary.

The symptoms of this disease are often related to blood circulation disorders, most commonly in the lower limbs. Initially, there may only be mild discomfort, but if not properly managed, it can lead to tissue necrosis or amputation. Notably, about 40% of patients have no obvious symptoms in the early stages of the disease, so high-risk groups (such as those with hypertension or diabetes) should undergo regular vascular examinations. The following sections outline the characteristics and changes of various symptoms by stage.

Early Symptoms and Signs

The early symptoms of peripheral artery disease are often mistaken for general fatigue or discomfort during exercise, making them easy to overlook. The main signs include:

• Intermittent Claudication: Pain or heaviness in the calf or thigh muscles during walking, which alleviates with rest, only to recur upon resuming walking.
• Muscle Fatigue in the Legs: Even after mild activity, the calf or buttock muscles may feel fatigued much sooner than those of healthy peers of the same age.
• Cold Extremities: The affected limb (usually the lower limb) often feels abnormally cold, even in a warm environment.

Some patients may exhibit atypical signs, such as pale skin on the toes or soles, or reduced hair growth. These signs may be related to local blood supply insufficiency, but usually require medical examination for confirmation.

Other Early Warning Signals

In addition to the main symptoms, the following phenomena should raise awareness:
- Weakening or absence of venous pulsation
- Prolonged capillary refill time in the foot (e.g., more than 5 seconds for color to return after pressure is applied to the foot)
- Decreased venous blood oxygen saturation leading to limb cyanosis

Common Symptoms

When arterial blockage exceeds 50%, symptoms become significant and frequent. The main symptoms include:

• Exercise-Induced Pain: Sharp pain in the calf, thigh, or buttock muscles occurs immediately during walking or climbing stairs, requiring immediate cessation of activity for relief.
• Changes in Skin of the Limbs: The skin on the feet or legs may appear pale or bluish, feel dry and lack elasticity, with noticeably slowed hair and nail growth.
• Temperature Difference: The affected limb may be more than 3 degrees Celsius cooler than the healthy limb, and the skin may lose normal tactile sensitivity.

About 30% of patients may experience "rest pain at night," where burning pain occurs in the toes or soles even when completely at rest, severely affecting sleep quality. Such symptoms usually indicate that arterial blockage has reached a critical point, requiring immediate medical evaluation.

Systemic Symptoms Associations

Although the main symptoms are concentrated in the lower limbs, peripheral artery disease often accompanies systemic vascular issues. About 40% of patients may develop heart disease or stroke, so the following associated symptoms should be noted:

• Angina or irregular heartbeat
• Dizziness or blurred vision (possibly associated with insufficient blood supply to the brain)
• Blood pressure differences (a difference of more than 20 mmHg between the arms)

Disease Progression and Symptom Changes

As the condition worsens, symptoms exhibit a stepwise deterioration pattern. The first stage is characterized by pain induced by activity, and as it progresses to the second stage, pain may also occur at rest. The third stage may present with tissue ischemic necrosis, with specific changes as follows:

In the mid-stage, patients may observe:

• Prolonged Pain Duration: Pain that previously relieved after 10 minutes of rest gradually extends to requiring more than 30 minutes of rest.
• Increased Pain Intensity: Pain escalates from mild discomfort to severe pain, even affecting nighttime sleep.
• Skin Tissue Changes: Unexplained ulcers may appear on the toes or heels, with surrounding skin possibly showing dark purple or black borders.

Severity of End-Stage Symptoms

When arterial blockage exceeds 70%, irreversible tissue damage may occur. Symptoms at this stage include:

• Painless Ulcers: Nerve damage leads to reduced pain sensation, but the tissue is severely ischemic.
• Melanosis: Psoriasis-like black patches appear on the toes or soles, accompanied by tissue necrosis.
• Absent Pulses: The pulse in the dorsalis pedis or popliteal artery may be weak or completely absent upon palpation.

This stage may also accompany systemic metabolic abnormalities, such as elevated lactic acid levels and abnormal C-reactive protein markers, necessitating immediate vascular imaging tests.

When to Seek Medical Attention

The following situations require immediate medical assistance:

• Unexplained coldness in the limbs lasting more than 48 hours
• Foot ulcers that expand more than 1 cm within two weeks
• Venous blood oxygen saturation (SpO2) measurements showing a difference of more than 15% between the affected and healthy limbs
• Foot ulcers present without pain (which may indicate concurrent nerve damage and arterial blockage)

It is recommended to undergo Ankle-Brachial Index (ABI) screening every six months, especially for those over 60, with a history of smoking or diabetes. Any of the following should be considered emergency symptoms:

• Psoriasis-like black patches on the toes or soles
• Skin temperature of the affected limb significantly lower than the opposite side by more than 10 degrees
• Swelling and redness around the ulcerated tissue

Doctors may further arrange Doppler ultrasound or computed tomography angiography (CTA) to assess the degree of arterial narrowing. Early diagnosis can delay disease progression through medication or surgery, preventing irreversible tissue damage.

 

Frequently Asked Questions

Does regular exercise worsen the symptoms of peripheral artery disease?

Moderate exercise can actually improve blood circulation in the lower limbs, but initially, it may trigger intermittent claudication (e.g., calf pain during walking). It is recommended to engage in regular exercise, such as walking training, under medical guidance, which can enhance muscle efficiency in utilizing blood and help alleviate symptoms in the long term rather than exacerbate them. During exercise, one should avoid excessive fatigue and closely monitor bodily responses.

How do the symptoms of peripheral artery disease differ from those of varicose veins?

The typical symptom of peripheral artery disease is leg pain during exercise (such as calf soreness after walking), while varicose veins often manifest as leg swelling, protruding veins, or a feeling of heaviness. The causes of the two conditions differ: the former is due to arterial blockage leading to insufficient blood supply, while the latter is due to venous blood return obstruction. If symptoms are confused, vascular ultrasound or Doppler examination is necessary for clear differentiation.

How does diet affect the alleviation of symptoms in peripheral artery disease?

A low-salt, low-fat, and high-fiber diet can lower blood pressure and cholesterol, slowing the progression of atherosclerosis. It is advisable to increase the intake of foods rich in Omega-3 (such as deep-sea fish) and antioxidants (such as berries and leafy greens), while controlling blood sugar and blood lipids. Avoid high-sugar and high-trans fat diets to reduce vascular inflammatory responses.

What non-invasive treatments can improve arterial blockage besides medication?

Vasodilators or antiplatelet medications can control symptoms, but physical therapy such as intermittent pneumatic compression can temporarily improve blood circulation. Additionally, quitting smoking, controlling hypertension, and managing high cholesterol are crucial. Severe blockages may require angioplasty or surgery, but this should be determined by a physician's assessment.

Why is early diagnosis of peripheral artery disease crucial for prognosis?

Early detection can delay disease progression through medication and lifestyle adjustments, preventing advancement to limb ischemia or even necrosis. Untreated patients may face increased risks of amputation or complications such as heart disease or stroke due to worsening arterial blockage. It is recommended that individuals experiencing intermittent claudication or cold sensations in the lower limbs undergo Ankle-Brachial Index (ABI) or vascular imaging examinations for early intervention.