Physical and Emotional Symptoms of Low Serotonin

Serotonin deficiency is linked to pain, fatigue, depression, and more

Serotonin is a chemical messenger that helps with regulating mood. It sometimes acts like a hormone as well. Given all the roles it plays, it makes sense that having low serotonin can cause such a range of symptoms, both physical and emotional.

Symptoms of low serotonin include:

  • Depression
  • Negative thoughts
  • Anxiety
  • Irritability
  • Low energy
  • Fatigue
  • Memory problems
  • Changes in sleep patterns
  • Chronic pain
  • Changes in appetite
  • Binge eating
  • Loss of interest in sex

This article goes over what serotonin does, the range of possible low-serotonin symptoms, how low serotonin is diagnosed, and what you can do to boost your levels, if needed.

Sad woman suffering from insomnia while sitting on her bed
demaerre / Getty Images

What Serotonin Does

Serotonin is a regulator of many processes in the body. When it's out of whack, these processes are no longer regular.

Serotonin's dual nature as a neurotransmitter and hormone means that it's found throughout your body. Perhaps surprisingly, there's more serotonin in your gut than in your brain. The effects of low serotonin can be many, and seemingly unrelated symptoms may, in fact, be all related to it.

Take fibromyalgia (FMS) and chronic fatigue syndrome (CFS or ME/CFS), for example. Both are thought to be tied to serotonin deficiency. Irritable bowel syndrome (IBS) also involves serotonin dysregulation and happens to be extremely common in those with either of these conditions.

Learning to spot the signs of low serotonin can help you get a diagnosis and treatment.

Physical Symptoms of Low Serotonin

Some of the physical symptoms linked to low serotonin are:

  • Chronic fatigue even though you get adequate rest
  • Disturbed sleep
  • Loss of appetite or carb cravings (possibly from the body's attempt to make more serotonin)
  • Hot flashes and temperature changes that are not 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 Symptoms of Low Serotonin

Emotional symptoms associated with low serotonin 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

The presence of emotional symptoms does not confirm a mental health issue. However, serotonin is involved in certain mental illnesses, such as major depressive disorder.

Talk to your healthcare provider about if you have any of these symptoms of low serotonin.

How Do I Know If My Serotonin Levels Are Low?

Measuring neurotransmitters is not a reliable way to diagnose low serotonin. Instead, healthcare providers rely on a review of your symptoms to make a diagnosis.

If you have physical and emotional symptoms that you think could be from low serotonin, it’s important to reach out to your primary care provider or a mental health provider for an evaluation.

Getting Help

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911 without delay.

For more mental health resources, see our National Helpline Database.

How Can I Raise Serotonin Levels?

There are many ways to fix low serotonin. Some people find that a combination of strategies work best for raising their serotonin levels and keeping them in a range that supports their physical and mental health. 

Antidepressant medications like SSRIs, SNRIs, MAOIs, and tricyclics can treat low serotonin. Your provider may prescribe one to you. Know, however, that these drugs can take some time to work.

In the meantime, your provider can suggest other strategies that might help boost your levels, including:

  • Eating a nutritious diet that includes foods like nuts and seeds, animal protein, and soy, as well as probiotic rich fermented foods
  • Exploring herbs and supplements like ashwagandha
  • Getting plenty of fresh air and sunlight during the day
  • Being physically active in a way that you enjoy
  • Making quality sleep a priority
  • Managing your stress levels
  • Reaching out for support from family and friends and/or providers

Continuing these strategies even after you start medication can also be helpful.

Before trying any supplements, talk to your provider—especially if you're taking prescription medications like antidepressants.


Serotonin is an important brain chemical that also works like a hormone. If you don't have enough serotonin, you can have physical and emotional symptoms that can be disruptive to your daily life.

Conditions like chronic fatigue syndrome (CFS) and fibromyalgia might be related to serotonin deficiency.

If you think you might have low levels of serotonin, talk to your provider. There are different ways to raise your levels and keep them up so you can feel and function at your best.

Frequently Asked Questions

  • Does low serotonin cause OCD symptoms?

    Low serotonin has been noted in people with obsessive-compulsive disorder (OCD). However, research has not confirmed a causal connection.

  • Is dizziness a symptom of low serotonin?

    Declining serotonin levels can cause dizziness. This may be because the vestibular system, which preserves a sense of balance, has many serotonin receptors—structures that allow messages from serotonin to be received.

  • Is anger a symptom of low serotonin?

    Aggression (hostile action) has long been an established symptom of low serotonin, but research also indicates that anger (the feeling) may be one as well.

  • What causes a drop in serotonin levels?

    Low serotonin can happen because your body does not make enough or it does not use it efficiently. There are likely several factors that cause or contribute to this. These may include genetics, stress, chronic pain, and nutritional deficiencies.

17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Berger M, Gray JA, Roth BL. The Expanded Biology of SerotoninAnnu Rev Med. 2009;60:355-366. doi:10.1146/

  2. Becker S, Schweinhardt P. Dysfunctional Neurotransmitter Systems in Fibromyalgia, Their Role in Central Stress Circuitry and Pharmacological Actions on These SystemsPain Res Treat. 2012;2012:741746. doi:10.1155/2012/741746

  3. Padhy SK, Sahoo S, Mahajan S, Sinha SK. Irritable bowel syndrome: Is it "irritable brain" or "irritable bowel"J Neurosci Rural Pract. 2015;6(4):568-577. doi:10.4103/0976-3147.169802

  4. Meeusen R, Watson P, Hasegawa H, Roelands B, Piacentini MF. Central Fatigue: The Serotonin Hypothesis and Beyond. Sports Med. 2006;36(10):881-909. doi:10.2165/00007256-200636100-00006

  5. Pakalnis A, Splaingard M, Splaingard D, Kring D, Colvin A. Serotonin Effects on Sleep and Emotional Disorders in Adolescent MigraineHeadache. 2009;49(10):1486-1492. doi:10.1111/j.1526-4610.2009.01392.x

  6. Aggarwal M, Puri V, Puri S. Serotonin and CGRP in MigraineAnn Neurosci. 2012;19(2):88-94. doi:10.5214/ans.0972.7531.12190210

  7. Cowen PJ, Browning M. What has serotonin to do with depressionWorld Psychiatry. 2015;14(2):158-160. doi:10.1002/wps.20229

  8. Nautiyal KM, Hen R. Serotonin receptors in depression: from A to BF1000Res. 2017;6:123. doi:10.12688/f1000research.9736.1

  9. Young SN. How to increase serotonin in the human brain without drugsJ Psychiatry Neurosci. 2007;32(6):394-399.

  10. UC San Diego Health. Good mood foods.

  11. Lopresti AL, Smith SJ, Malvi H, Kodgule R. An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled studyMedicine (Baltimore). 2019;98(37):e17186. doi:10.1097/MD.0000000000017186

  12. Sansone RA, Sansone LA. Sunshine, serotonin, and skin: a partial explanation for seasonal patterns in psychopathology?Innov Clin Neurosci. 2013;10(7-8):20-24.

  13. American Psychological Association. Working out boosts brain health.

  14. McGill. The brain from top to bottom.

  15. Stanford Medicine. Understanding Obsessive-Compulsive and Related Disorders.

  16. Smith PF, Darlington CL. A possible explanation for dizziness following SSRI discontinuation. Acta Otolaryngol. 2010 Sep;130(9):981-3. doi:10.3109/00016481003602082

  17. University of Cambridge. Research provides new insight into why some individuals may be more aggressive than others.

By Adrienne Dellwo
Adrienne Dellwo is an experienced journalist who was diagnosed with fibromyalgia and has written extensively on the topic.