Four Stages of PAD and What They Mean

Peripheral artery disease affects an ever-growing number of patients in the United States and around the world. However, PAD remains a relatively less known concern among patients, and our medical system still needs to catch up with screening for this disease. To fully understand PAD, it’s best to compare it to coronary artery disease; imagine the plaque build-up in the arteries of the limbs – the legs and the arms. As with any artery, plaque can build up on the walls of the peripheral arteries and occlude the vessel, slowing down blood flow. To this end, PAD is often an indicator of future coronary artery disease.

As the Blockage Gets Worse, so Do the Symptoms.

Unfortunately, the arterial blockage associated with PAD cannot be fully reversed, so catching it earlier is very important. Within electrophysiology, we have technical classifications like the Fontaine system; however, discussing the four stages of PAD gives patients a better idea of the symptoms at each level.

Stage 1: Asymptomatic PAD

Asymptomatic peripheral artery disease is the first of the four stages, and as you can tell from the name, it does not have any symptoms at all. At this point, any occlusion of the peripheral arteries is minor, and blood flows well to the extremities. However, this does represent the beginnings of a more significant problem in the future.

Most patients are not actively tested for PAD, and as such, many are diagnosed incidentally at this stage. This means blockages within the peripheral arteries are found during a checkup or diagnostic testing – usually a cardiovascular screening. Catching PAD at this early stage is good news, as there are plenty of treatment options. We will also strongly encourage our patients to embark on lifestyle changes, including improved diet, greater exercise, and elimination of smoking.

Stage 2: Claudication

The second stage of PAD is the first that comes with symptoms. Patients usually experience symptoms (pain most often) in their lower extremities and in their calves. Patients mistake this for muscle pain because it usually happens after exercise, like an extended period of walking. However, we can distinguish PAD from generic muscular pain because it is reproducible every time the patient exercises. Typically, with muscle pain, as the muscle becomes accustomed to the exertion, it will no longer cause pain.

Further, the pain usually disappears after some rest, whereas muscle pain from overexertion would continue for at least a day or two longer. At this point, a treatment regimen must begin and lifestyle improvement remains critical at this stage.

Stage 3: Critical Limb Ischemia

Ischemia is the term for restricted or reduced blood flow to an area of the body or organ. At this point in the PAD continuum, we have reached a critical stage, reflected in the name. Blood flow has been compromised to the point that pain occurs even at rest and possibly through the night. For some, skin sores may develop as some blood doesn’t reach the extremity. Others will see a loss of hair at the extremities.

Now is the time for more invasive treatment. One of the best options is balloon angioplasty and the subsequent placement of a stent. A bypass may be necessary if the blockage cannot be managed with the angioplasty.

Stage 4: Acute Limb Ischemia

ALI, or acute limb ischemia, involves almost complete loss of blood flow to the affected limb due to arterial plaque build-up. This emergency can result in rapid loss of limb function and tissue death without immediate care. The signs will be obvious: significant pain, tingling sensations, loss of pulse, cold in the extremities, the extremity turning pale, and even paralysis. Delayed care often leads to amputation. Even if amputation is avoided, many patients will have to live with permanent muscular and nerve damage.

Naturally, we don’t want our patients to reach anything resembling stage 3 or stage 4 and, as such, encourage them to stay in touch with their cardiologist and let them know about any unusual sensations they may be experiencing that could signify PAD or anything else. Being under the care of a qualified cardiologist with extensive experience in PAD is critical to diagnosing and managing this condition. Please schedule a consultation with us to learn more about what you may be experiencing.