Sudden onset may suggest deep vein thrombosis, acute heart failure, cellulitis, etc.

Gradual onset may be seen in most types of chronic oedema.

Sudden worsening of a pre-existing oedema may raise the suspicion of DVT, heart failure, recurrence of malignancy in patients with known cancer, cellulitis.

It is important to determine the extent of the oedema and which parts of the body are involved. In secondary lymphoedema the swelling should be confined to areas of known lymphatic damage. If more extensive oedema is present, other causes such as heart failure, liver disease, renal disease, advanced malignancy, etc. should be considered.

Arm oedema is most commonly seen as a result of treatment for breast cancer, but may be post-thrombotic or rarely due to primary lymphoedema. Superior vena caval obstruction should be considered in patients with recent onset bilateral arm oedema.

Head and neck/facial oedema may be seen in isolation as a result of rosacea, head and neck trauma, surgery and radiotherapy for head and neck cancer and recurrent head and neck cancer but may also be part of a more widespread problem, e.g. in nephrotic syndrome and some types of primary lymphatic dysplasia.

Pain can be present in all of the different types of chronic oedema. The type of pain may sometimes help with differentiating the cause of the swelling but is not usually diagnostic.

People with lymphoedema often described a tightness / heaviness as the swelling develops. Severe pain is not usually a feature unless cellulitis or another acute problem develops.

In venous oedema, patients often describe an aching of the legs as the day goes on. This is typically relieved by elevation and compression garments.

Neuropathic pain may occur in a number of situations e.g. associated with carpal tunnel syndrome and upper limb swelling, in those with oedema in advanced cancer and nerve compression from recurrent tumour and in diabetic patients with chronic oedema of the legs and peripheral neuropathy.

Lipoedematous legs are often tender and painful.

Comorbidities / predisposing factors e.g. chronic long term conditions, obesity, etc. should be considered.

Many patients with chronic oedema of the legs have diurnal variation of the oedema being worse as the day goes on and reducing overnight. This reduction may be typically minimal in patients with chronic lymphoedema. In some women there may be a cyclical pattern of oedema. Head & neck swelling tends to be worse in the morning and improves as the day goes on.

Taking a family history is useful in considering patients with possible inherited primary lymphoedema.

Many drugs may cause peripheral oedema or exacerbate existing chronic oedema. The most common ones to consider are: calcium channel antagonists; corticosteroids; nonsteroidal anti-inflammatories (NSAIDs); alpha-blockers and sex hormones; etc. (For a more detailed description of drugs which can cause oedema, see Keeley 2008).