Hypovolemia is a life-threatening complication that occurs when the loss of blood or other bodily fluids causes the body’s fluid volume to drop.

When you lose more than 15% of your fluid volume, your body cannot pump enough blood, meaning you do not receive enough blood or oxygen.

The best way to prevent hypovolemia is to be aware of the causes and symptoms so you can recognize when you are at risk and seek immediate medical attention, if needed.

Hypovolemia symptoms can differ based on the cause of your hypovolemia. Hypovolemia can be caused by short-term trauma or result from a long-term medical condition. Some general symptoms include:

• Clammy, cool skin
• Confusion
• Light-headedness
• Turgor, decreased skin elasticity
• Decreased urination
• Fatigue
• Irritability
• Low blood pressure
• Muscle cramps
• Pale skin
• Rapid breathing
• Sweating
• Thirst
• Weakness

There are two general categories of hypovolemia causes, based on the type of fluid loss. If you have hemorrhagic hypovolemia, your main fluid loss is blood. If you have non-hemorrhagic hypovolemia, your main loss is other fluids.

Hemorrhagic Hypovolemia

Hemorrhagic hypovolemia is caused by excessive bleeding, such as from a gastrointestinal (GI) bleed, ectopic pregnancy, or a brisk posterior nosebleed (a nosebleed starting in the back of your nasal cavity). It can also occur due to traumatic bleeding, as from a deep cut, gunshot wound, or internal bleeding. When your bleeding is severe, your blood cannot clot fast enough, and the bleeding is uncontrolled.

Shock can occur once fluid loss reaches 15% of your total body fluid volume. While your heart is still beating, there isn’t enough blood to carry oxygen and nutrients to your organs. As shock worsens, your organs don’t receive what they need to work properly. If not treated, organs can start to fail, which can be life-threatening.

Non-Hemorrhagic Hypovolemia

You may also lose blood in non-hemorrhagic hypovolemia, but it is not the main fluid you are losing. Non-hemorrhagic hypovolemia is caused by:

If you are experiencing diarrhea, excessive sweating, or vomiting, you lose fluids rapidly. When you have a severe burn, your body has an inflammatory reaction, causing your blood vessels to release fluids. This fluid loss occurs rapidly, which can lead to hypovolemia.

Checking your blood pressure is the fastest and easiest way for your healthcare provider to diagnose hypovolemia. When the top number of your blood pressure measurement, your systolic pressure, is low, the pressure from your bloodstream pushing against your blood vessels is low. This indicates your fluid volume is too low.

Other indicators of hypovolemia are low body temperature and a weak, rapid pulse. Other tests your healthcare provider may perform include:

• Blood work: These tests provide information on kidney function, heart muscle damage, and complete blood cell count.
• Imaging tests: X-rays, computerized tomography (CT) scans, or ultrasounds are used to look for injuries and spontaneous bleeding.
• Heart tests: Echocardiograms and electrocardiograms examine the physical function of your heart.
• Endoscopy: For this medical test, your healthcare provider passes an endoscope (a thin, flexible tube with a tiny camera) through your mouth into your stomach. This helps them look for inflammation, ulcers, or growths without surgery.
• Colonoscopy: For this medical test, your healthcare provider uses an endoscope to look inside your colon (large intestine). The tube is gently inserted through your anus so they can check for polyps, inflammation, or signs of disease (like colon cancer).
• Urinary catheterization: This is when a thin, flexible tube is inserted into your bladder to measure how much urine is left after you go to the bathroom. This helps your healthcare provider check for infections, kidney problems, or other issues affecting your bladder and urinary tract.

If your fluid loss is critical or not treated right away, it can lead to organ failure from a lack of oxygen and, eventually, death.

Hypovolemia treatment depends on its cause and severity. Any medical conditions, including diabetes, anemia, and pregnancy, should also be considered. Treatment generally involves restoring fluid loss. Other steps that need to be taken are:

• Supplying intravenous fluid and electrolytes to restore fluid volume
• Keeping you warm to maintain body temperature
• Delivering oxygen to keep the body oxygenated
• Lying flat with feet elevated about 12 inches to increase circulation
• Giving a blood transfusion until you have the proper blood volume

Once your fluid volume is restored, fluid treatment is stopped to avoid accumulating excessive fluid. Too much fluid could lead to heart and breathing problems. You are monitored afterward to ensure you are stable, or you may need additional fluids.

Preventing hypovolemia is easier than trying to treat it because hypovolemia can quickly result in an emergency called hypovolemic shock.

Know the causes of hypovolemia to recognize when you are at risk. If you are at risk, keep yourself hydrated to prevent fluid loss. Be aware of the signs and symptoms of hypovolemia so you can get immediate medical attention.

If your hypovolemia is not treated right away, it can lead to serious complications. These may include:

• Acute kidney failure: Your kidney function reduces or stops due to the drop in fluid pressure and lack of oxygen
• Acute liver failure: Your liver function reduces or stops due to the lack of oxygen
• Gangrene: A loss of blood supply and oxygen to your arms and legs causes tissue death and could lead to amputation
• Heart attack: A lack of blood flow to a part of your heart causes those cells to die and can lead to death
• Ischemic stroke: Low blood volume and pressure reduce blood flow to your brain, which can prevent your brain from getting the oxygen it needs, leading to damage
• Hypovolemic shock: Death or dysfunction of multiple organs from a lack of blood flow and oxygen

Hypovolemia is a life-threatening complication resulting from a drop in your fluid volume by more than 15%. If not treated immediately, it can lead to serious complications like organ failure and death.

Seek immediate medical attention if you suspect you or someone else is experiencing hypovolemia. The fastest treatment is intravenous fluids. The best prevention is knowing the causes and symptoms so you recognize when you are at risk.