Idiopathic oedema is the term for fluid retention which it not caused by a known medical condition. It is most common in women and can sometimes worsen as you get older. Although there is no cure for idiopathic oedema, having a healthy diet which is low in salt can make a real difference. Support stockings and regular exercise are also beneficial.
What is idiopathic oedema?
Oedema is the medical term for fluid retention. Idiopathic is a term which means unknown cause. Idiopathic oedema is therefore a condition of mild fluid retention where the cause is not fully understood.
Oedema can also be caused by various conditions, including diseases of the heart or kidney. Therefore it is very important that your doctor checks you for any condition that may be causing your swelling (for example, problems with the heart, kidneys or blood vessels). If these have been ruled out by tests then the diagnosis may be idiopathic oedema. For more information, see the separate leaflet on Oedema.
People with idiopathic oedema are otherwise healthy and do not have a kidney or heart disease to account for their oedema. Idiopathic oedema is not serious but can be a nuisance.
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Who has idiopathic oedema?
Idiopathic oedema mainly affects women in their middle years. It can become worse as you become older. Many women find that the oedema worsens at certain times of the month (usually just before a period).
What causes idiopathic oedema?
The underlying cause seems to be due to fluid leaking out of the small blood vessels into the tissues. Why this occurs in some people is not clear. It is usually worse after you have been standing for long periods, as there is increased pressure in your veins when standing compared to lying down. Going on long journeys or sitting still for long periods of time can also worsen the swelling.
One possible cause is the retention of salt (sodium). When the body retains salt it also holds on to fluid and thereby may cause some oedema.
A possible cause of fluid retention often overlooked by people and difficult to diagnose is due to binge eating alternating with strict dieting. This can cause intermittent fluid retention.
What are the symptoms?
Mild swelling of the feet, hands, tummy (abdomen), breasts and face may occur. This is worse at the end of the day and may disappear after a night's rest. Rings may need to be taken off and looser clothes may need to be worn in the evening.
Many people with idiopathic oedema find that they weigh about two kilograms (four pounds) more in the evening compared to the morning. You should use the same scales to weigh yourself, after you have been to the toilet, morning and evening.
Idiopathic oedema treatment
Idiopathic oedema is not an easy condition to treat and cannot often be cured. Many people are reassured that their fluid retention is not due to a serious medical condition. Learning to live with it and changing into loose clothes in the evening are all that is required for most people.
However, the following tips may be helpful:
Avoid prolonged standing
This may not always be easy, especially if you are in a job which requires you to stand for long periods of time. Wearing support stockings or tights will often help to reduce swelling of ankles and legs. There are now many different types and sizes, meaning they are fairly comfortable to wear. Many of the tights and stockings are now available on prescription from your doctor.
Many people with fluid retention are overweight and losing weight can make a big difference to improve the oedema. A gradual weight loss (rather than fasting and bingeing) is recommended.
Idiopathic oedema diet
What you eat may help with fluid retention. In particular:
- Salt (sodium) restriction - idiopathic oedema can often improve greatly if you reduce your salt intake. One way is to stop adding salt to food. Also reduce the amount of processed foods you eat, as these often contain large amounts of salt.
- Eating foods rich in potassium - eating potassium-rich foods can actually help to reduce the salt levels in the body and so may improve the oedema. Potassium-rich foods include most fruits, especially bananas and also tomatoes. You should not take potassium supplement tablets though.
Many people take 'water' tablets (diuretics) for oedema due to other medical conditions. However, in idiopathic oedema, diuretics may make things worse in some people, as they alter the salt and water balance of the body. They are not necessarily the easy answer to the problem. However, they can help some people. A doctor is the best person to discuss whether or not they may help you. Also, there are different types of diuretics, and some are not advised for idiopathic oedema. So, it is best to speak with a doctor before using any diuretic.
Further reading and references
Trayes KP, Studdiford JS, Pickle S, et al; Edema: diagnosis and management. Am Fam Physician. 2013 Jul 1588(2):102-10.
Ely JW, Osheroff JA, Chambliss ML, et al; Approach to leg edema of unclear etiology. J Am Board Fam Med. 2006 Mar-Apr19(2):148-60.
Dunnigan MG, Henderson JB, Hole D, et al; Unexplained swelling symptoms in women (idiopathic oedema) comprise one component of a common polysymptomatic syndrome. QJM. 2004 Nov97(11):755-64.