Fluid retention (oedema) describes an excess of fluid in the tissues caused by an incorrect leakage from the blood vessels, especially the capillaries. Fluid in the body exists in three compartments. In the cells (intracellular), in the tissues (interstitial) and in the blood vessels. There is constant interchange between these three compartments and they are all ‘fed’ by fluid taken in from the bowel.

The balance is maintained by osmosis (where water molecules follow larger molecules through blood vessel and cell walls) and by chemical messengers that increase or decrease the size of the pores in the blood vessels and cell walls.

There are many reasons why fluid will build up in the interstitial compartment but in principle this is either because protein leaks from the capillaries pulling water with it or the fluid cannot enter the cells because of a protective fat/protein layer that is laid down around the cells. Specific areas of the body may become oedematous because of a blockage in the drainage system (the lymph system), which can occur through infections causing elephantiasis, trauma or tumour.

Many conditions affect capillary permeability but hormone imbalance is one of the most common. Low thyroid levels and imbalance between oestrogen and progesterone and hormones produced by the kidneys and nervous system all affect the size of blood vessels and their permeability. Water is attracted into tissues by osmosis. Osmosis is a physiological reaction caused by molecular electromagnetic attraction that, put simply, pulls water through a membrane until there are equal numbers of water molecules either side. A similar situation will occur if there is a lack of sodium or potassium and other electrolytes and minerals within the bloodstream. Excess salt or sugar in the tissues will pull water into them, as will toxins. This latter process is an attempt by the body to dilute down the potentially poisonous effects.

Simple back-pressure caused by obstruction to venous flow or heart failure will literally force fluid through the capillary pores. Symptoms of oedema or water retention are dependent upon where the fluid has settled. The biggest complaint is about water that settles in the ankles and lower legs, hands and fingers, around the face and jaw and the midriff. The more serious places for oedema to occur are within the vital organs such as the brain and lungs. The latter two are associated with medical complications and need urgent attention.

Fluid in the lower limbs is often associated with venous obstruction and is commonly found in pregnancy and obesity. More serious conditions such as heart failure and diseases of the liver (through which the main vein of the body – the vena cava – passes) causes back-pressure and forces fluids into the tissues.

More generalized oedema is often noted with hormonal fluctuation and pre-menstrual syndrome is notorious for having this as one of its most awkward symptoms. Shoes become tight to wear, and rings obstruct circulation to the fingers.

Dietary deficiencies will lead to poor electrolyte, amino acid and mineral content, allowing water to move cosmetically into the tissues and a food allergy may create a toxic state within the tissues that causes water to be pulled in for dilution. Other toxins such as alcohol and its breakdown product aldehyde, cigarette by-products and other drugs of abuse may all cause a toxic state requiring dilution as well as creating a chemical effect directly on the permeability of the capillaries. Orthodox drugs may well induce oedema for the same reason.

One of the major causes of water retention that is commonly overlooked is, paradoxically, dehydration . Although it is not immediately obvious why not drinking enough water may cause an excess of water in the tissues, the mechanism is simple. If not enough water is ingested, the individual cells in the body recognize dehydration. They attract fluid into themselves and when replete will surround their outer walls with a waterproof lipid/protein protection. This cover is generally a cholesterol-based compound manufactured in the liver and is a cause for raised cholesterol levels in the bloodstream.

Despite the cells being hydrated and therefore normal metabolic function progressing without illness forming, the body will recognize the dehydration and give instructions to hold water in the system because there is not enough. The bloodstream will provide fluid to the body tissues, particularly to the fat stores, thereby creating oedema and the midriff effect so commonly associated with PMS. This leaves the bloodstream concentrated, triggering further reflex water retention.

Another less respected cause of water retention is the build-up of toxins in the system. The body will often hold water to dilute poisons that may be found in the interstitial and cellular compartments, thereby rendering the concentration less dangerous. The characteristic bloating often found after drinking or abusing drugs is caused by a combination of dehydration and toxic build-up.


It is important to rule out underlying hormonal or biochemical changes that may be due to conditions such as hypothyroidism and diabetes. Diseases of the heart, liver and kidney, the former two leading to venous back-pressure and the latter to electrolyte disturbance, all need to be ruled out.

Review any drug prescription via the doctor who prescribed in case one of its side effects is water retention. This may need to be changed or removed.

Review the diet. Restrict salt and processed foods, which are inevitably high in sodium content.

Consider testing for food allergies. Whether this is required may be established by using a Detox diet or fast for three days, ensuring adequate water intake. If an improvement occurs, food allergy is probable.

Drink plenty of water. As described above, the mechanism is paradoxical but the more water that is drunk, the less the retention is maintained. Normal input should be half a pint per foot of height at the least but in cases of water retention this should be doubled. Water intake may need to be restricted in cases of fluid retention caused by heart, liver or kidney problems. Discuss this with your practitioner.

Water retention associated with the hormonal cycle may benefit from vitamin B6 (20mg per foot of height divided into two doses) taken with breakfast and supper.

The homeopathic remedy Natrum muriaticum 30 taken four times a day for five days may shift the problem and can be repeated up to twice a month.

Herbal treatments such as Uva ursi, Herberus and juniper can be utilized but should be considered as a drug or a diuretic and should be prescribed by a herbalist rather than taken off the shelf.

Any retentive disorder (one that forms lumps, bumps or cysts) including water retention may be a bodily reflection of a mental or spiritual attitude. Water retention associated with depression or an inability to express is literally ‘holding it in’ and it is necessary to confront these emotions. Counselling is invaluable in water retention that does not seem to have an underlying physical illness associated with it or does not respond to the naturopathic recommendations above.