Can stress cause fever?

This stress epidemic is definitely a cause for major concern among thought leaders and policy makers, all over the world. The ripple effects of such appallingly high numbers of chronically stressed people could be potentially devastating, for humanity and the planet at large.

Among the many ill-effects of stress, we are going to look at one that is not very widely discussed - stress-induced fever or psychogenic fever.

What is Psychogenic Fever?

Psychogenic fever refers to a rise in the body’s core temperature (Tc) in response to an intensely stressful situation or a persistent elevation in the core temperature, due to chronically high stress levels. It is a psychosomatic disease, which means that it occurs in the absence of any organic cause, like a bacterial infection, for instance.

Psychogenic fever is especially common among women, children and adolescents. Many parents of young children and teenagers are often stumped for answers when their kids report having a fever, without any obvious underlying cause. Such cases are cause for significant worry among parents, especially considering children who report such symptoms might also display other signs of maladjustment and have generalised psychosocial challenges which might make it challenging for them to cope adequately with their academic and social lives.

There are two common manifestations of psychogenic fever: The first kind is a high fever of upto 40°C [104°F] as a result of an acute incidence of severe stress, due to trauma or an emotional upheaval. Alternatively, it can also manifest as a sustained increase in temperature, in the form of a low-grade fever between 37°C [98.6°F] and 38°C [100.4°F].

What are the Mechanisms Underlying Psychogenic Fever?

We do not completely understand the mechanisms behind psychogenic fever yet. However, we do know that they are not mediated by the same processes that underlie fevers of a non-psychogenic cause.

Fevers that are caused by an infection, are mediated by pro-inflammatory mediators called cytokines. In regular fevers, substances called pyrogens, which may be released by the infecting organism or endogenously by the body, trigger the production of a cytokine called PGE2 (a type of prostaglandin), which in turn increases the temperature setting in the hypothalamus, which leads to an increase in body temperature. (Click Here to know more about how this works).

Psychogenic fevers, on the other hand, are typically caused by mechanisms that don’t involve cytokines. Typically, they are not accompanied by an inflammatory response. Therefore, there is no increase in blood levels of prostaglandins or interleukins during a psychogenic fever. However, it has been observed that they do go along with increased levels of catecholamines in the blood. Catecholamines are a class of endocrine hormones that include noradrenaline and adrenaline, which are released by the adrenal glands. They are responsible, along with the sympathetic nervous system, for mediating the stress response. They are released during moments of threat or distress and bring about a state of heightened arousal, commonly known as the “fight or flight” response.

Many different kinds of psychological stress can cause an increase in temperature. For instance, it can be nervousness or performance anxiety before an important exam, the death of a loved one, intimidation (physical or psychological) etc. Usually, in average subjects, the temperature returns to normal a few hours after the stressful situation concludes. However, in people exposed to chronic stress over long periods of time, this hyperthermic response is altered in a few distinct ways, which will be discussed further in a subsequent section of the article.

How Is Psychogenic Fever Differentiated From Physiological/Normal SIH?

Even in average people enjoying good health, there are temporary spikes in Tc during emotional stress. This is known as “Stress Induced Hyperthermia” (SIH). Although they have a similar mechanism, a diagnosis of psychogenic fever is much more clinically significant and therefore, it is important to be able to distinguish it from physiological/normal SIH.

Firstly, in healthy individuals, although emotional events are associated with an increase in Tc, this increase is usually very small and is usually <1 °C. Moreover, their Tc seldom goes beyond 37.5°C [99.5°F]. In patients with psychogenic fever however, the spikes can be much more pronounced and in severe cases, the Tc can be as high as 40-41 °C [104-105.8°F]. The severity of the temperature increase depends on the magnitude of the stress response.

Additionally, while a normal SIH response does not usually cause any other symptoms, people with psychogenic fever may often report symptoms such as headache, insomnia, nausea fatigue and abdominal pain. A clinician might also be able to diagnose the condition based on the fact that such patients are usually high in neuroticism and anxiety and present as such. Psychogenic fever is also strongly correlated with other mental health/mood disorders such as bipolar disorder, post traumatic stress disorder (PTSD) and borderline personality disorders.

How Do We Get Stressed?

Before we get into the neurological basis of psychogenic fever, it is essential to understand the neurological basis of stress and anxiety. As mentioned previously, stress and anxiety are responses of the nervous system to help us cope with stressors and threats from the external environment. These responses originate in very deep, primitive regions of our brain. Therefore, we share these responses, on a fundamental level, with species much further away from us on the evolutionary tree.

Much of what we understand about psychogenic fever and its mechanisms is from studies conducted on rats.These experiments subjected rats to various types of stresses such as being transferred to a different cage, removing cage-mates and being subjected to the presence of a dominant animal or intruder and carefully studying the fluctuations in their core temperature. This phenomenon has also been noticed, subsequently, in many other species in addition to rats, such as mice, chimpanzees, sheep and squirrels, just to name a few.

It was found that when exposure to the stress was repeated over a prolonged period of time, it started having curious effects on Tc.

• When a rat was exposed to stressors at periodic time intervals, it resulted in a learned/anticipatory increase in temperature. i.e. There was an increase in Tc during the hour before the scheduled stress, even when the stressor was not present.
• Prolonged periods of stress translated to a higher hyperthermic response, in terms of magnitude, in response to novel stressors (i.e The temperature spike during novel stressful situations, the likes of which hadn’t been experienced before, was higher than usual).
• In addition to the hyperthermic response, rats began to show depressive behaviour when the stressors persisted over long periods of time.
• These stress-related changes persisted long after the stressor was removed from the environment and could even be observed several days after the disappearance of the stressor.

These are all very significant findings that help us understand the basis of such responses to stress. Though humans share a lot of these responses, as a part of our primitive neural circuitry, layered onto them, is our massive and sophisticated cortical apparatus, which gives us powers accessible to no other species on the planet. Unlike other species, humans possess a sharp memory and a vivid sense of imagination. This, again in no small part, is responsible for a lot of our achievements. But, this can also conspire to make us more prone to these stress-related illnesses. Humans can experience a stress-response by merely remembering something that happened in the distant past or by imagining potential negative situations that they could experience. It isn’t a surprise then, to find out that a lot of patients with severe psychogenic fever have a history of trauma, usually from early on in their lives.

The human brain, especially the part of our brain called the neo-cortex, possesses an incredible property called plasticity. Neuroplasticity refers to the property of the brain to literally realign itself, structurally, to adjust to the demands being put on it; i.e. it essentially rewires itself, constantly, to better adapt to our lifestyles and the tasks we assign to it. It is because of this property that we are able to learn languages, play instruments or get progressively better at any skill. However, much as this property confers immense benefits on us, both as individuals and as a species, it is a double-edged sword. The brain does not discriminate between positive and negative behavioural patterns; It just constantly adapts and re-structures itself to get better and more efficient at reproducing habitual patterns of thought, emotion and behaviour. Therefore, the more negative emotions we experience, the more readily our brain conjures these negative responses. In simpler terms, the more a person is anxious or stressed, the better their brain gets at being anxious and stressed. Understanding this vicious loop is absolutely vital to being able to appreciate the full extent of the problem that mental health issues pose to caregivers, family members and medical practitioners worldwide.

How Is Psychogenic Fever Treated?

• Unlike fevers that occur due to infectious causes, stress-induced fevers can not be treated by anti-pyretic medications or NSAIDs (Non-Steroidal Anti-Inflammatory Drugs), such as paracetamol, ibuprofen or indomethacin. This is because psychogenic fevers, as we discussed earlier in the article, are not mediated by the same mechanisms that are behind infectious fevers.
• Psychogenic fevers are usually treated with psychotropic drugs that display sedative and anxiolytic properties.
• Although medication might provide a certain measure of relief from the symptoms, a thorough assessment needs to be done to understand the key triggers that set off anxiety in the patient. Therapy and counseling directed at helping the patient cope with the perceived threats in their life are essential to ensuring positive outcomes in the long term. The more stuck a person feels in their negative loops and destructive behaviour patterns, the more sorely they might need such external help, in order to get better.
• Benzodiazepines have been shown to ameliorate psychogenic fever. Common drugs used from this category include diazepam, alprazolam and chlordiazepoxide. 5-HT1A receptor agonists like buspirone and flesinoxan have also been shown to attenuate SIH. Fluoxetine (more commonly known as prozac), a popular anti-depressant medication has also been shown to be effective in some trials.
• Relaxation techniques such as mindfulness meditation, yoga and tai chi have been shown to be incredibly effective in helping people cope with anxiety and stress. These practices allow people to gain some “distance” from their relentlessly ticking minds and observe their own mental activity from a more objective standpoint. They also relax brain activity and have been shown to have a calming effect on the heart rate.

Summing Up

Higher levels of stress are being reported worldwide. A previously unseen proportion of anxiety and depressive disorders are being recorded today. A measure of contemplation, calmness and just good old slowing down seems to be in order for us, as a society. We are also faced with a pressing need to face ourselves, both as a collective unit and as individuals, and ask ourselves what the truly important things are in life. We might be more industrially capable than ever before, but at what cost? Are conveniences, gizmos and distractions worth our inner peace and stability? These questions might seem cheesy and banal, but this sorry state of affairs is only getting worse. Nevertheless, there is probably need to get quite so grim, after all; Now more than ever, people in distress have access to a whole lot of material and guidance through the internet. Be it Eastern breathing techniques or hands-on yoga training, it can all be accessed through a few clicks, right from your bedroom. However, it would be very naive of us to be complacent and dismiss the issue of stress and anxiety. It might not be far fetched at all to assume that this stress epidemic is only going to get worse in the near future, if we don’t collectively learn to take a breather.