In this Medical Monday series, we’re talking about how your doctor reaches a diagnosis of common conditions associated with coagulation. it may help if you read the introduction first before today’s topic of DVT. Altogether we’re covering
- DVT, Deep Vein Thrombosis
- Post-thrombotic syndrome
- PE, Pulmonary Embolism
- Pulmonary hypertension
- AF, Atrial Fibrillation
- Heart Valve conditions – aortic and mitral
- Heart attack
Your story is very important to help the doctor make the diagnosis. For a DVT, the story can be quite different depending on the size and site of your clot. For some people the first thing they notice is some discomfort in the leg a bit like cramp (or in the US ‘Charley horse’). This can last for a day or so before they start to get concerned that the discomfort is not settling. This can be followed by some local tenderness and ankle swelling. The leg swelling can be very variable, in some cases there is slight swelling around the ankle but in others the whole leg can swell dramatically. Obvious inflammation with the leg turning slightly red is less common, but some people do have slight fever and feel unwell.
Questions your doctor may ask
Your doctor will want to know how long you have had the problem and did anything in particular bring on the symptoms. Have you recently had surgery? or have you been unwell? or had an injury? Have you previously had a blood clot? or do you have a family history of blood clots? Your doctor will also want to know what medication you are taking. It’s important to know if women are taking the pill or if there is any possibility they could be pregnant. In older people, a blood clot can be the first sign of cancer, so your doctor may ask questions relevant to this, such as have you lost any weight? do you have a persistent cough? are you a smoker? or have you noticed any change in your bowel motions?
What your doctor may find
Doctors will look at your leg first to see if it is swollen or red and then feel your leg to see if any areas are tender or warm, and squeeze the leg around your ankle to see if there is any fluid under the skin. They may measure the circumference if the swelling is not obvious. Your doctor is also likely to look in your groin to see if there are any swollen lymph nodes or tenderness over the vein there. If you have any other symptoms, he may listen to your chest, especially if you have mentioned that you are a bit short of breath, as your doctor wants to be sure you have not also had a pulmonary embolus.
Your doctor will probably use a scoring system called the Wells score to assess the likelihood of you having a clot (this is discussed in full, in tomorrow’s post).
Tests you may have
If your doctor thinks there is a high likelihood you may have a clot, you will have an ultrasound of your leg as the next test, but if it is not so clear you will be sent for a blood test called the d-dimer. It is likely your doctor will do some other blood tests at the same time to check your blood count, your kidney function and your liver function. These will be important if you need treatment.
The d-dimer (to be discussed in Wednesday’s post) is used to exclude a clot. If the test is negative a clot is unlikely. If it is positive you will need an ultrasound scan.
What it could be
- Cellulitis or inflammation in the skin of the lower leg looks very similar to a blood clot but needs quite different treatment.
- A Baker’s cyst. This is a fluid filled swelling behind the knee that some people get with arthritis of the knee. The cyst can rupture and cause pain like a DVT.
- Varicose veins. These are swollen superficial veins of the leg. Sometimes they become inflammed and tender like a blood clot.
- Superficial thrombophlebitis is when a blood clot forms in a superficial rather than deep vein. it may need anticoagulants or anti-inflammatories.
- Severe cramp and muscle tears can also give similar symptoms.
It is important to get the diagnosis correct as these conditions all need different treatment. If anticoagulants are given in cases of trauma or a Baker’s cyst, they can make the leg worse.
If you’ve had a DVT, was it diagnosed like this?