Fluid overload

Fluid overload symptoms

The excess fluid circulating around the body can cause waterlogging of the lungs, leading to breathlessness. The medical term for this is acute pulmonary oedema. 'Acute' means 'of quick onset'.

Alternatively the overloading process can occur over a longer period of time and cause additional symptoms like swelling in the lower leg and high blood pressure. The type of swelling that occurs in the legs is called pitting oedema. This means that when the swelling is pressed with a finger, it leaves an indentation, or a 'pit'.

Can fluid overload cause death?

This depends on the cause of the fluid overload - how serious it is and and whether it can be treated.

Even if the fluid overload is not caused by a heart condition, if it is not treated the extra pressure on the heart eventually leads to heart failure. This causes tiredness, shortness of breath and swelling of the legs and feet. Heart failure is a complex condition which can result in a lower life expectancy for some.

What causes fluid overload?

The heart and kidneys interact to control fluid volume and the sodium content in the body. This system is quite complex.

• Treatment with fluid can be a cause. It is sometimes difficult to calculate how much fluid the body needs. This can happen when nutritional fluid or blood is given through a drip. The risk of overload may be increased if you are elderly, you have had a major injury or operation, or your kidneys or heart do not work as well as they should,

• Sometimes the problem is not so much extra fluid as too much sodium. Sodium is a chemical that occurs naturally in the body and needs to be at a certain level in the blood and other body fluids. If too much sodium is given, the body will retain water to try to correct this.

• People with heart failure may have fluid overload,

• People whose kidneys suddenly stop working properly (acute kidney injury or chronic kidney disease) can be similarly affected.

How is fluid overload diagnosed?

A number of conditions produce signs and symptoms that resemble fluid overload, and these need to be excluded. These conditions include:

• Lung problems, such as blood clots, infections, asthma.

• Heart problems, such as inflammation of the covering of the heart (pericarditis).

• Problems with the venous circulation or lymphatic circulation.

• Metabolic disorders causing a low protein level in the blood (hypoproteinaemia).

• Liver disease.

• Thyroid disease.

• Kidney disease.

Will I need any tests?

It's not surprising that with all these conditions to rule out you may need several tests. These may include:

• Heart tests: heart tracing (electrocardiogram, or ECG) and ultrasound scanning of the heart (echocardiogram, or echo).

• Chest X-ray.

• Blood tests to check your kidney function, blood count, liver function, blood gases.

• A special test for heart failure, called B-type natriuretic peptide (BNP).

• Charts to check how much you drink and pee and any weight changes in response to treatment.

How to treat fluid overload

The treatment depends on your symptoms and the underlying cause. The possible treatments include:

• 'Water tablets' (diuretics): see the leaflets on Loop Diuretics and Thiazide Diuretics for more information.

• Mineralocorticoid/aldosterone receptor antagonists (MRAs) - eg, spironolactone and eplerenone - like diuretics, also prevent the build-up of fluid.

• In some situations you may be advised to restrict fluid or salt intake.

• You may be asked to weigh yourself daily.

• Other treatments such as dialysis may also be needed for severe fluid overload.

What is the outlook for fluid overload?

This depends on the underlying cause and how well you were before the fluid overload occurred. For example:

• If the fluid overload was due to a problem with your heart, the outlook (prognosis) depends on how treatable your heart condition is.

• If the fluid overload resulted from being given too much fluid during intravenous treatment, the outlook will depend on the reason why you needed a drip in the first place.

• If you were given it because you had just had a simple operation but were well beforehand, the outlook should be good once the overload is corrected.

• However, if intravenous treatment was given because you had a serious problem such as extensive burns, correcting the overload may be more complicated.