Ajax Harwood Clinic
Blood clots
A blood clot in a deep vein — usually a leg — is a DVT; if part of it breaks away and lodges in the lungs that is a pulmonary embolism, which is the reason clots are taken so seriously.
Get help straight away if
These are uncommon, but they need same-day care — go to an emergency department, do not wait for an appointment.
- Sudden breathlessness, chest pain that is worse when you breathe in, coughing blood, or feeling faintThese can mean a clot has travelled to the lung. Call 911 or go to an emergency department now — this is not something to wait on.
- A leg that becomes swollen, hot and painful, particularly on one sidePossible deep vein thrombosis. Needs assessment the same day.
What usually happens
Clots are treatable, and treated early they usually resolve without lasting harm. The danger is almost entirely in the delay.
They often have a trigger — recent surgery, a long period of immobility, pregnancy, a cast, cancer or its treatment, some hormone medications, or a long flight. Sometimes there is no trigger at all, and that changes what we look for afterwards.
Treatment thins the blood so the clot stops growing while your body breaks it down. It does not dissolve the clot instantly, which is why the leg can stay swollen for a while after treatment has started and working.
How long treatment lasts depends on why the clot happened. A clot after an obvious, temporary trigger is treated differently from one that appeared for no clear reason.
At your appointment
If a clot is suspected we will arrange urgent testing — usually an ultrasound for a leg, or a scan for the lungs — because this is diagnosed by imaging rather than by examination alone.
We will go through what might have triggered it, including medications, recent travel, surgery, immobility and family history.
If treatment starts we will explain what to watch for, what raises bleeding risk, and what to do about missed doses — the practical things that decide whether treatment is safe.
We will agree how long you are on it and when that gets reviewed.
Worth asking
- Do we know why this happened, and does that change how long I need treatment?
- What raises my bleeding risk while I am on this?
- What should I do if I miss a dose?
- Are my family members at higher risk, and should they know anything?
Curious what your doctor is weighing up? The clinical tool we use for thrombosis is open to anyone — it is detailed and written for clinicians, and you are welcome to read it.
Open the clinician reference →General health information for Ajax Harwood Clinic patients and the public — not medical advice, and not a substitute for seeing your own doctor. In an emergency call 911.