Stress can have a major impact on your physical and mental health. While chronic stress can lead to mental health disorders like depression and anxiety, it can also make you physically ill, and may even contribute to long-term conditions like heart disease.
In addition, stress can cause a fever even when there is no underlying illness or infection. This is known as a psychogenic fever.
"A phenomenon has been described where stress seems to raise core body temperature in the absence of other inflammatory processes such as infection or injury," says Katrina Miller Parrish, MD, chief quality and information executive for L.A. Care Health Plan.
What is a psychogenic fever?
A psychogenic fever is an increase in body temperature caused by stress. It is sometimes referred to as stress-induced hyperthermia.
Psychogenic fevers are diagnosed when body temperature is above 98.6 degrees Fahrenheit (37 degrees Celsius) while someone is experiencing acute or chronic stress, according to a 2015 scientific paper in the journal Temperature. Other typical causes of fever, like infection or illness, must be ruled out.
Doctors don't understand exactly why this happens, according to Miller Parrish, but they believe that either the brain increases temperature in response to stress, or that stress hormones interact with the endocrine system and lead to an increase in body temperature.
For example, a 2020 study published in the journal Science found that the stress response affects the hypothalamus in rats, which is the area of the brain that controls body temperature. But more research is needed to determine whether this is the case for humans.
Psychogenic fevers can occur at any age, and seem to occur more commonly in females than in males. However, because there hasn't been a large body of research, there isn't precise and consistent data.
A 2009 study published in the journal BioPsychoSocial Medicine examined health records of 2,705 patients who visited the Psychosomatic Department of the University of Occupational and Environmental Health in Japan. Of those patients, 2% were diagnosed with psychogenic fevers. The patients with these fevers were ages 11 to 82; roughly 30% of them were male, while roughly 70% were female.
"It is difficult to know the true prevalence of psychogenic fever because it may not be reported as much as it exists," Miller Parrish says. "If we took all people with any kind of stress, and noted a portion of that total had stress-induced hyperthermia, it would be quite a high number."
How to tell if stress is causing your fever
A psychogenic fever exhibits many of the typical fever symptoms, such as:
In the case of acute stress, like if you suddenly receive bad news or experience the death of a loved one, you might feel these symptoms and recognize a psychogenic fever. But cases are rarely so clear cut. That's especially true with chronic stress, like taking care of a loved one who is ill, which can build up over time and result in psychogenic fever symptoms.
To diagnose psychogenic fever, other physical causes of fever must be ruled out, Miller Parrish says. It's important to note that fever most commonly occurs with illness or injury. So, if you're also experiencing symptoms like nasal congestion or coughing with fever, it's likely indicating an underlying cause for the fever other than stress, like the flu or a cold.
If you experience fever regularly but can't easily identify the underlying cause — like an illness or injury — you should keep a fever journal, Miller Parrish says. Record what temperature you're experiencing, the symptoms you have, and how long the fever lasts. If the unexplained fever continues, you should see a doctor.
"If that persists for days to weeks, it would be prudent to see a doctor to rule out causes that need medical treatment," Miller Parrish says. "If those causes are ruled out or treated and the high temperatures persist, other psychological and de-stressing interventions may help."
How to treat a psychogenic fever
If you are experiencing a psychogenic fever, you'll need to work to reduce your stress levels.
Most psychogenic fevers are short-lived and resolve on their own. Decreasing stress through therapy and non-medical interventions like mindfulness can also help treat psychogenic fevers.
"If a fever is due to stress, it is essential to decrease the stress," Miller Parrish says. First, you'll need to identify what's stressing you out. It might be one specific incident, or an on-going stressor like untreated anxiety, depression, or work-related burnout. Once you've identified the source of the stress, you can address the root cause of the fever.
"Depending on the cause, the antidote could be cognitive behavioral or other psychological therapy, meditation, yoga and practices that focus on decreasing a stressful state, or perhaps even medication to treat the issue," Miller Parrish says.https://www.insider.com/can-stress-cause-fever