Physical and Emotional Symptoms of Low Serotonin

Many symptoms of fibromyalgia (FMS) and possibly chronic fatigue syndrome (CFS or ME/CFS) are believed to be tied to low levels of the neurotransmitter serotonin. These can include pain, fatigue, low energy, depression, negative thoughts, irritability, anxiety, abdominal problems, binge eating, and a reduced interest in sex. The assortment of symptoms can be confusing and bewildering, not to mention no fun to live with.

But as varied as the problems are, they're not the only effects related to serotonin, which is both a neurotransmitter (in your brain) and a hormone (in the rest of your body.)

Sad woman suffering from insomnia while sitting on her bed
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What Serotonin Does

Serotonin is a regulator of all kinds of processes, so it's no wonder that when it's out of whack, nothing is regular. That's why you feel like your body is falling apart and your symptoms don't make any sense.

Serotonin's dual nature, as a neurotransmitter and hormone, means it's found all over your body. In fact, there's more serotonin in your gut than in your brain. That may explain why illnesses such as irritable bowel syndrome (IBS) are extremely common in FMS and ME/CFS: IBS involves serotonin dysregulation as well.

By recognizing symptoms of serotonin dysregulation, you may be able to not only understand your symptoms but actually improve your chances of proper diagnosis and treatment.

Physical Serotonin-Related Symptoms

Measuring neurotransmitters is not a reliable way of diagnosis. Instead, your healthcare providers rely on symptoms for making diagnoses. For that reason, it's important for you to know which symptoms may be linked to serotonin.

What we call "low" serotonin may come from a couple of different causes: either your body doesn't make enough, or it doesn't use it efficiently.

Some of the major physical symptoms linked to low serotonin are:

  • Chronic fatigue in spite of adequate rest
  • Disturbed sleep
  • Loss of appetite or carb cravings, possibly due to the body's attempt to make more serotonin
  • Hot flashes and temperature changes that aren't linked to your environment
  • Headaches
  • Stomach pains

Certainly, some of these symptoms can crop up in anyone's life from time to time. The key here is to recognize whether you have clusters of symptoms that tend to occur together. Serotonin levels can fluctuate, leading to symptom flares and remissions (times when symptoms are gone or at low levels).

Emotional Serotonin-Related Symptoms

The presence of emotional symptoms in no way implies that FMS or ME/CFS are psychological or psychiatric illnesses. In fact, we know that these conditions include numerous biological abnormalities. FMS is generally considered a neurological condition, and both of these illnesses are sometimes called neuroimmune diseases or neuroendocrine-immune diseases.

Serotonin is also involved in certain mental illnesses, such as major depressive disorder. Even in these cases, serotonin dysregulation represents a physical problem.

Emotional symptoms include:

  • Social withdrawal
  • Sadness and frequent crying spells
  • Low self-esteem and self-confidence
  • Changes in personality
  • Feeling emotionally sensitive and taking things personally
  • Irritability

Talk to your healthcare provider about if you have these symptoms. Depression is common in FMS and ME/CFS, and it is treatable.

A Word From Verywell

If you think your serotonin is low, talk to your practitioner. You may need to consider treatments that raise your available amount of serotonin.

Probably the most common treatment is medication: your healthcare provider may prescribe antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), or tricyclics. Some supplements and your diet can influence serotonin as well.

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