Shivering: Causes, treatment, and when to see a doctor (original) (raw)

Shivering occurs most commonly when a person is cold. When muscles move, they generate heat. Therefore, when a person is cold, their muscles begin to quickly tighten and loosen over and over again to produce heat. This is known as shivering. It is usually temporary and should stop once the individual warms up.

However, shivering can also be a symptom of physical or mental illness.

Below are potential causes of shivering:

1. Fever

Other than being cold, the most common cause of shivering is fever. The average body temperature is around 98.6° F. Doctors usually define a fever as a body temperature higher than 100.4°F.

Fever usually occurs as a result of infection, but inflammation or an allergic reaction can also increase body temperature. Some people with a fever may also have signs of flu, but others will have no additional symptoms.

If a person has other symptoms, particularly a stiff neck, rapid heartbeat, or shallow breathing, they should seek medical advice urgently. If they have no other symptoms, they will only need to visit a doctor if the fever lasts for more than 3 days.

2. Psychogenic movement disorders

For some people, stress or mental health factors can cause shivering and other involuntary movements. This usually occurs due to a psychogenic movement disorder, which can affect any part of the body.

A doctor who specializes in medical conditions affecting the brain, called a neurologist, will usually diagnose psychogenic movement disorders. They may look for the following characteristics when making a diagnosis:

There is often no underlying brain or nerve damage. Instead, shivering is the body’s response to stress.

Doctors will often treat psychogenic movement disorders with a combination of mental health therapy and physical therapy.

3. Postanesthetic shivering

Shivering can occur when a person regains consciousness after a general anesthetic. This is known as postanestheric shivering.

A person’s temperature may drop during a surgical procedure, which can cause them to shiver when they wake up after the operation is over. Anesthetics can also affect the body’s ability to regulate temperature, which can make it difficult for the body to warm up quickly after an operation.

Doctors will usually check a person’s temperature and provide them with blankets or heaters if necessary.

4. Fear, excitement, or stress

Strong emotions can cause a person to shake or shiver. This is often due to a surge of adrenaline in the body. Adrenaline is a hormone that triggers the body’s fight-or-flight response.

Shivering should stop after the adrenaline leaves the body. For many people, this will happen very rarely, perhaps during a particularly exciting or frightening moment. For those who experience chronic stress, adrenaline surges and shaking can be more frequent.

5. Anxiety

Similarly, when a person experiences anxiety, it may present with physical symptoms, such as shaking. This is also due to a surge of adrenaline.

Treatment for anxiety may include therapy, medication, and lifestyle changes. Activities that might help a person to manage their anxiety include exercising, practicing mindfulness and meditation, and spending time with supportive friends and family.

6. Tremor

Involuntary trembling, shaking, or shivering can be due to a medical condition called essential tremor. Essential tremor is a neurological condition, meaning that it relates to the brain. Evidence suggests that essential tremor may affect up to 5% of the global population.

Tremors can also be a symptom of Parkinson’s disease. This is a disorder that affects an area of the brain and tends to develop gradually.

7. Low blood sugar

If a person has not had food for a long time, the level of glucose in their blood can drop. This low blood sugar can cause a person to shiver or feel shaky.

For people who have diabetes, this will be known as hypoglycemia, and it can be severe. People with diabetes should check their blood glucose regularly to prevent their levels from dropping too low.

8. Sepsis

Sepsis is an overwhelming response of the body to infection, and it often occurs in connection with lung, skin, gut, or urinary tract infections.

One of the symptoms of sepsis is shivering. Other symptoms may include confusion, fever, warm skin, lightheadedness, a rapid heartbeat, and a skin rash.

Sepsis is a medical emergency. People with sepsis will need prompt treatment with antibiotics in a hospital.

Shivering is usually temporary. If it occurs due to a fever, low blood sugar, or a strong emotion, it should resolve once a person treats the underlying cause. They can:

Other causes of shivering may be due to an underlying medical condition. If a person is concerned, they should note any other symptoms and seek medical advice.

Shivering can be a more severe symptom for older adults or people with an underlying health condition. Older adults are often less able to regulate their body temperature so they may become cold more quickly. Keeping warm in cold weather is essential for good health.

Fever increases the heart rate and makes breathing faster. This can be serious if a person has a heart or lung condition.