Blood Clot In The Leg (DVT) Symptoms, Causes And Treatment

A blood clot in the leg is otherwise known as Deep Vein Thrombosis (DVT). The condition is not confined to the leg, and can occur in the thighs or pelvis. DVT can be a dangerous condition in serious cases and if left untreated, especially when the clot breaks free from its original position. In this case it can travel through the bloodstream and may cause a blockage that can lead to very serious complications. When this happens, the patient is suffering from a pulmonary embolism. In this article we will take a look at the causes of DVT, what can be done to treat it, and the many blood clot in the leg symptoms that may manifest.


Let’s start by looking at the many symptoms that may be indicative of a blood clot in the leg. It is worth knowing that some of these can be associated with other conditions, hence proper medical diagnosis is essential. The following are the main symptoms of DVT:

  • Gradually increasing pain in the leg and thigh area
  • Swelling of the leg and thigh
  • Redness in the painful area
  • Warm when touched
  • Cramp in the leg, especially prevalent at night
  • Pain when bending the foot
  • Pale blue or white discolouration on the skin

What is important to understand is that as many as half of people who suffer from DVT will not experience any symptoms. This can make diagnosis particularly troublesome in many cases.


A blood clot in the leg is not always a serious issue, but if left unattended it can cause complications. Many clots simply dissolve without any help, but others may break free and travel around the veins. Blood clots are caused by many factors – we will cover the causes of blood clots in the section below – and are associated with long distance travel in which the patient is sat in one place for some time. This is why it is strongly recommended that you move around on long flights, or stop the car and take a walk regularly on long road journeys. The problems with clots occur when they break free – as mentioned – in which case they cause a pulmonary embolism; this is when a clot causes blockages in the veins that feed the heart with blood. In such cases there can be serious problems, and even death. Tens of thousands of people die thanks to pulmonary embolism each year, many of whom were not aware that they had a blood clot in the first place. It is estimated to be the third most common cause of death in the western world.


In recent years DVT has become strongly associated with long distance travel, particularly on aircraft where the individual remains in one position for a long time. This is not the sole cause of DVT, however, and there are many conditions and situations that can bring on a blood clot. Here are some of the more common causes:

  • Trauma to the lower body that may have damaged the veins
  • Changes in blood flow, perhaps caused by illness
  • Prolonged immobility, thanks to bed rest or illness, and long distance travel
  • Recent surgery, especially in the orthopaedic, gynaecologic, or heart surgery areas
  • Obesity – a common cause of DVT
  • Heart failure or cardiac arrest
  • Childbirth
  • Some medicines, including birth control pills
  • Many types of cancer
  • Altitude of more than 14,000ft
  • A number of genetic conditions and many diseases
  • The ageing process

The above are the more common causes of blood clots in the leg, and as you can see they are especially varied and cover a lot of different areas. This goes some way towards explaining why the condition is not uncommon.


To be able to treat DVT the patient must first be correctly diagnosed (see the section on how to detect a blood clot in the leg for further information) and the location of the clot properly determined. In the first instance the patient will most likely be prescribed a drug to thin the blood; this not only helps to prevent the formation of further clots, but also lowers the risk of a pulmonary embolism. There may be special requirements for some patients who also suffer from other conditions, and these will be assessed by the doctor in charge of the case.

In cases where the clot is determined to be a minor one the treatment can be carried out as an outpatient procedure; in more serious cases the patient will need to be in hospital for careful observation while the clot is treated. The treatment, known as anticoagulation, will last for as long as it takes to remove the clot, and this depends on the size, location and seriousness of the blood clot. Patients may also be asked to wear compression stockings in order to help prevent the formation of more clots. It should be noted that treatment for DVT is very much individualised as per the patients’ situation. A side note: we are talking about blood clots in the leg, but they can also occur in the groin, and in the arms, with similar results and treatment methods.

If an anticoagulation drug is required, be sure you know what your doctor is prescribing. Warfarin and Pradaxa have always been popular options, but with the flurry of pradaxa lawsuits lately, the use of anticoagulation drugs is dwindling. If you are currently taking Pradaxa, keep yourself informed by monitoring for the latest updates.

How To Detect a Blood Clot In The Leg?

As we mentioned earlier a blood clot in the leg can be difficult to determine: in many patients there are no notable symptoms. There are several methods of looking for DVT, and if a person suspects they may be suffering – perhaps thanks to persistent leg cramps at night – they should seek medical diagnosis. Here are some of the methods a doctor will use to diagnose DVT:

  • Ultrasound: this painless and safe method is the most commonly used, and utilises high frequency sound waves to search the veins for clots. The only problem is that it can often fail to spot smaller clots.

The following are rarely used, having been overtaken by ultrasound technology:

  • Venography: once the standard test but now very rarely used, this is the process of injecting coloured dye into the bloodstream to look for blockages. It has been largely usurped by the use of ultrasound technology.
  • Impedance plethysmography: a method of using electrodes to measure the volume of blood flowing in the veins.
  • CT scan: used for detecting clots in the lungs, rarely for those in the legs.

How Long Does It Take a Blood Clot In The Leg To Dissolve?

This depends entirely upon the individual case, and on the treatment prescribed. Some patients may experience a blood clot and – as we have already noted – will never know thanks to a lack of symptoms. Others may have symptoms of DVT that last for many weeks, even months. Warfarin is the most common anticoagulant drug and is very effective, in general, the first time blood clot sufferer will be required to take the drug for at least six months, in order to be sure that the risk of recurrence is minimised. The patient will most likely be in hospital, in the first instance, for up to a week. Many patients do suffer from recurring blood clots thanks to medical conditions, and it is wise to ensure that the drugs taken for these do not inspire DVT.

We hope that, with this article, you have been able to understand blood clots in the leg (DVT) and what causes them, how to treat them, and when to seek medical attention. As a last word, remember that long periods of sitting or standing in the same position are common causes of DVT, so try to make sure you take a break and move around on a regular basis.

Written By Jack Johnston

Jack Johnston, M.D., is board-certified by the American Board of Family Medicine. Dr. Johnston received his undergraduate degree from the University of Illinois at Champaign. In 1995 he graduated with a Medical Degree from the Stritch School of Medicine at Loyola University of Chicago. Dr. Johnston’s residency in Family Medicine was completed at Northwestern Memorial Hospital. After completing an Integrative Medicine Fellowship, Dr. Johnston served as Chief Resident in 2001.


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