Wells Score Calculator for Pulmonary Embolism

2-level classification:

Pulmonary embolism unlikely.

Proportion of patients with confirmed PE can be expected to be around 12% in this group.

3-level classification:

Low risk of pulmonary embolism.

Proportion of patients with confirmed PE can be expected to be around 30% in this group.

Wells score calculator for pulmonary embolism is an essential diagnostic tool based on different clinical features to evaluate pulmonary embolism. This Wells score calculator provides information regarding the chances of pulmonary embolism to occur. In addition, this calculator follows a typical list of clinical features to evaluate the risk of pulmonary embolism. Moreover, this Wells score calculator for pulmonary embolism is usually applied after a detailed history and physical suggestions to get accurate results.

This article is all about the important details of pulmonary embolism and its associated signs and symptoms. Moreover, this article also provides detailed information regarding the usage of the Wells score calculator for pulmonary embolism. It will also help to know the specific Wells criteria to clarify the concepts regarding this calculator. Let us take a deep dive into the primary content related to the Wells score calculator for pulmonary embolism.

What do you understand by the term pulmonary embolism?

The pulmonary term is specifically used for the lungs. Moreover, embolism defines the obstruction or blockage of the arteries due to any foreign material. This combined term indicates the blockage of the associated arteries of the lungs due to any foreign substance. This blocking of blood vessels by foreign material can be of any type. Most commonly, this foreign substance is a blood clot. Blood clots usually form in the deep veins of the legs and travel back toward the lung, causing a blockage in the arteries of the lungs.

Foreign or blockage substances can be of the following types.

  • Amniotic fluid – this fluid can get trapped in the blood circulation during the labor phase to cause obstruction in the lung vessels.
  • Air- air embolism or trapped air appears as a complication during the administration of a central venous catheter. It is a type of pulmonary embolism based on the blockage substance.
  • Fatty tissues – fatty tissues are usually found in the bone marrow of long bones. Fractures affecting the long bones can release fatty tissue in the blood circulation, leading to pulmonary embolism.
  • Metastatic cancerous tissue can get trapped in the blood vessels, leading to pulmonary embolism.
  • Any other foreign body can cause a pulmonary embolism.

What are the consequences of pulmonary embolism?

Pulmonary embolism can affect the human body in a variety of ways. Here we will discuss the important aspects related to pulmonary embolism. Pulmonary embolism can cause a sudden increase in pulmonary arterial pressure with an increased overload in the right ventricle. It defines that the right ventricle will have to overcome more resistance. In these conditions, it becomes quite insufficient very rapidly, leading to ventricular failure. Right ventricular failure is the most common cause of death in cases of pulmonary embolism.

Due to insufficiency of the right ventricle,  the cardiac output of the right ventricle also decreases. It indicates that less blood is leaving and entering the left ventricle through the right ventricle. In this way, it results in decreased systemic blood pressure and decreased perfusion of the vital organs. The blood supply to the heart decreases. Cardiomyocytes (contractile units of the heart containing cardiac muscles) get a lower amount of oxygen and perform poorly. These cells may die due to decreased oxygen, leading to myocardial infarction or heart attack.

These are the major consequences associated with pulmonary embolism. There are several other minor events related to pulmonary embolism to affect multiple organs of the body in different ways.

What are the typical symptoms associated with pulmonary embolism?

Pulmonary embolism exhibits a variety of symptoms that are quite unspecific and may occur with different medical conditions. For this reason, it becomes quite difficult to diagnose pulmonary embolism to deal with the main cause. This is the only answer for the creation of the Wells score calculator for pulmonary embolism. There is a list of the typical symptoms of pulmonary embolism ranging from the main leading symptom to the least appearing symptom.

  • Dyspnea – shortness of breath or having difficulty breathing normally
  • Pleuritic chest pain – it is a type of chest pain that increases as you inhale or exhale
  • Substernal chest pain – this symptom is similar to cardiac angina pain. It can cause difficulty to diagnose pulmonary embolism.
  • Cough
  • Hemoptysis – blood appearing in the cough. It is one of the deciding criteria for the Wells score calculator. This symptom is present only in 8% of the patients suffering from pulmonary embolism.
  • Fever
  • Syncope

The other common symptoms also include hypotension or shock conditions. These problems require immediate clinical management. Pulmonary embolism is most commonly associated with deep vein thrombosis. So the symptoms of deep vein thrombosis also fall in the Wells criteria to diagnose pulmonary embolism.

What is the behind story for the creation of Wells criteria?

In a study published in 2001, Doctor Phil Wells and colleagues offered a set of clinical criteria that helps in the assessment of the chances of pulmonary embolism. This system is designed by putting the patients into the pulmonary embolism risk group without doing any biochemical or imaging tests. It helps to diagnose the patients at their bedside following the Wells criteria. Thanks to this Wells criteria as it provides accurate results just considering the clinical parameters.

In addition, this Wells criteria help physicians to diagnose the patients having risk chances of pulmonary embolism. Moreover, it also helps to decide whether the patient needs to undergo D-dimer level tests first or imaging diagnostic tests.

How to use the Wells score calculator for pulmonary embolism?

This section will help you to understand the usage of the Wells score calculator for pulmonary embolism. Here is the way to use the Wells score calculator for pulmonary embolism.

  • Use the Wells score calculator only if you suspect your patient may have a chance of pulmonary embolism. For this, your patient must be hemodynamically stable.
  • Check the signs and symptoms of deep vein thrombosis. These symptoms include pain in deep vein localization and swelling in the leg. If the patient is having symptoms of deep vein thrombosis, assign 3 points to the patient.
  • Measure the heart rate of the patient. Auscultate the heart and palpate the pulse, and check their bedside ECG findings. If the patient has a heart rate greater than 100, assign 1.5 points. You can find your heart rate through our ECG heart rate calculator.
  • Check the parameters that whether the patient is having any previous surgery history in the last 4 weeks or not. Moreover, take a detailed history of whether the patient was immobilized in the previous 3 days. Surgery and immobilization add 1.5 points to the Wells score calculator.
  • Any previous history or diagnosis of deep vein thrombosis or pulmonary embolism also adds 1.5 points to the Wells score criteria.
  • Haemoptysis adds 1 point to the Wells score criteria.
  • Take a history related to cancer or cancer treatment in the present or previous 6 months. If yes, it will also add 1 point to the Wells score criteria.
  • The last thing you need to put your own opinion on is whether pulmonary embolism is the most likely cause or if there are any other main medical problems with an alternative diagnosis. The answer to this question is based on the physician’s experience. It also adds 3 points to the Wells score criteria.

These are the basic clinical history points you need to answer. Every point is important and adds a different score to the Wells criteria. The final score helps to know the risk group for the patient.

How to interpret the Wells score calculator for pulmonary embolism?

There are two ways to classify pulmonary embolism risk groups depending on the Wells score. These are as follows:

3-level classification by Dr. Phil Wells:

  • 0 to 1 point – low risk of pulmonary embolism (10%)
  • 2 to 6 points – moderate risk of pulmonary embolism (30%)
  • 7 and more than 7 points – high risk of pulmonary embolism (65%)

2-level calcification by Christopher study:

  • 0 to 4 points – unlikely to occur pulmonary embolism
  • 5 and more than 5 points – pulmonary embolism likely to occur (almost 50%)

It is recommended that patients with a Wells score of more than 5 are more likely to go for diagnostic imaging tests to diagnose pulmonary embolism. Moreover, the patients with a Wells score of less than 5 need to go for the D-dimer level. Low D-dimer level excludes pulmonary embolism.


Wells score calculator is mainly designed to properly diagnose pulmonary embolism. Pulmonary embolism exhibits a variety of symptoms and may appear with any other medical disease. Therefore, it becomes quite difficult to evaluate pulmonary embolism. For this reason, the Wells score calculator provides a quite accurate estimation to evaluate the chances of pulmonary embolism based on clinical history. This article is all about the Wells score calculator for pulmonary embolism and associated details to clear the concepts regarding the usage of this calculator. Use this calculator to get the best results.

Frequently asked questions (FAQs)

Can we use the Wells score for deep vein thrombosis evaluation?

Well’s score criteria are mainly for the assessment of pulmonary embolism. Wells criteria include the symptoms of deep vein thrombosis to evaluate pulmonary embolism. But, it is not used for deep vein thrombosis.

What do we understand by the Wells score of 6?

A Wells score of 6 indicates that you lie in the moderate risk group for pulmonary embolism. You must undergo proper imaging diagnostic tests to evaluate pulmonary embolism.

Back to top button