Fluid Overload - Symptoms and Causes

What are the symptoms of fluid overload?

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'.

If fluid overload goes on for a long term it eventually leads to heart failure. This causes tiredness, breathlessness and swelling of the legs and feet. The type of swelling that occurs is called pitting oedema. This means that when the swelling is pressed with a finger, it leaves an indentation, or 'pit'.

What are the causes of fluid overload?

The heart and kidneys interact to control fluid volume and the sodium content in the body. This system is quite complex. More information about it can be found in the separate article written for doctors, called Fluid Overload.

  • 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 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) can be similarly affected.
  • When something goes wrong with this system it's known as cardiorenal syndrome.

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  • Kim IY, Kim JH, Lee DW, et al; Fluid overload and survival in critically ill patients with acute kidney injury receiving continuous renal replacement therapy. PLoS One. 2017 Feb 14 12(2):e0172137. doi: 10.1371/journal.pone.0172137. eCollection 2017.
  • Byrne L, Van Haren F; Fluid resuscitation in human sepsis: Time to rewrite history? Ann Intensive Care. 2017 Dec 7(1):4. doi: 10.1186/s13613-016-0231-8. Epub 2017 Jan 3.
  • Glatz T, Kulemann B, Marjanovic G, et al; Postoperative fluid overload is a risk factor for adverse surgical outcome in patients undergoing esophagectomy for esophageal cancer: a retrospective study in 335 patients. BMC Surg. 2017 Jan 13 17(1):6. doi: 10.1186/s12893-016-0203-9.
Dr Laurence Knott
Peer Reviewer:
Dr Adrian Bonsall
Document ID:
29443 (v1)
Last Checked:
09 July 2017
Next Review:
08 July 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.