How Serotonin Deficiency And  Fibromyalgia Affects The Body

Understanding serotonin deficiency and fibromyalgia

What is serotonin deficiency?

Have you ever asked yourself what serotonin is? What is this neurotransmitter affecting our mood? 

Serotonin is a chemical messenger factor influencing feelings such as happiness, fear, and anxiety. Serotonin is responsible for boosting mood, and it is regulated in further locations like the digestive tract and maintains gut health. The remainder focuses on the central nervous system, blood platelets, and blood clots. Serotonin deficiency is a common contributor to mood problems leading to depression.1,2 

What is fibromyalgia?

Fibromyalgia affects about 2% of the population in the UK, and about 14,000 people are diagnosed annually with fibromyalgia3. Even if the percentage is not high or scary, fibromyalgia is a vague disease with an unknown cause and irritating symptoms. Fibromyalgia syndrome (FMS) is a chronic, complex, and heterogeneous disease with variable chronic symptoms, and no two people are the same. It is more common in women than men, with a ratio of 9 to 1.3

What are fibromyalgia symptoms?4

  • Widespread chronic pain all over the body with a lower pain threshold to normally non-painful  stimuli (hyperalgesia and allodynia)
  • Sleep disturbance
  • Fatigue
  • Headache
  • Depression and anxiety
  • Mental stress as problems in concentration, learning new things, and speech difficulty
  • In addition to digestive problems such as constipation, abdominal pain, and bloating, it may progress to irritable bowel syndrome
  • Hot flushes and temperature changes
  • Tingly  hands and feet 
  • Temporomandibular joint syndrome

The symptoms of fibromyalgia are changeable; they are considered episodes that may worsen or improve according to factors such as stress level, changes in the weather, and physical activity. 

What causes fibromyalgia?4

The triggering cause of fibromyalgia is unknown; it may be due to the abnormal levels of certain chemicals in the brain, the changes occurring in the central nervous system, the processes of pain messages carried around the body, or it may be genetic. 

There are possible triggers that stimulate the development of fibromyalgia:

  1. Emotional stress, including post-traumatic stress disorder or car accidents
  2. Physical stress can be an injury or surgery
  3. A viral infection like the Epstein-Barr virus affects bodily fluids
  4. Fibromyalgia may be associated with osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and temporomandibular disorder (TMD)

What tool is used to diagnose fibromyalgia? 

Fibromyalgia diagnosis is difficult because there are no specific tests to diagnose this condition, a blood test and an x-ray diagnosis to exclude other conditions such as thyroid problems and polymyalgia rheumatica. The diagnosis of fibromyalgia mainly depends on symptoms and varies from one patient to another.5

What treatment is required for fibromyalgia?

Treatment aims to improve symptoms and its function to support the quality of life notion. There is no single treatment for all fibromyalgia symptoms. It is not necessarily true that the treatment that can work for one patient will work for another.  

Three main treatments for fibromyalgia: 

  1. Self-help:
    • Exercises: Being physically active can ease fibromyalgia, it will reduce pain and improve your quality of life6
    • Relaxation and meditation: Decrease stress as it may worsen symptoms and cause them to flare up.6 Develop better-sleeping habits6
  1. Talking therapies7 

Acceptance and commitment therapy (ACT) helps reduce pain, improve sleeping quality, and deal with negative thoughts. 

Cognitive behavioural therapy (CBT) helps you deal with the disease by changing the way you think and behave. 

  1. Medications6 

Antidepressants help relieve the pain of fibromyalgia: 

  • Amitriptyline 
  • Citalopram 
  • Duolextine 
  • Paroxtine 
  • Fluoxetine 
  • Sertraline

How are serotonin deficiency and fibromyalgia connected?

Fibromyalgia patients have low serotonin levels, and those lower serotonin levels reveal more severe fibromyalgia symptoms like feeling pain and having depression and anxiety.8 Fibromyalgia is responsible for low vitamin D serotonin levels. Yet, the relationship between fibromyalgia is not fully understood.9 Research indicates that 60% of fibromyalgia patients have a serotonin and Vitamin D deficiency.10

What effects occur with a  low serotonin level?2

Low serotonin activity is associated with psychiatric diseases such as depression, attention deficit hyperactivity disorder (ADHD), anxiety, and post-traumatic stress disorder (PTSD)2.

Causes of low serotonin levels?11

  • Chronic stress
  • Lack of sunlight 
  • Lack of physical activity
  • Genetic factors 
  • Age-related  brain changes
  • Sleep cycle disturbance
  • Postmenopausal  symptoms
  • Pain
  • Toxic substances, such as heavy metals and drug use, cause permanent damage to nerve cells that are responsible for making serotonin
  • Poor diet may contribute to neurotransmitter building and imbalance 

What are the  symptoms  causing low serotonin level?2,11

  • Irritability may be due to low serotonin activity, as serotonin is responsible for regulating mood. 
  • Depression
  • Anxiety and panic attacks
  • Changes in appetite cause obesity or eating disorders
  • Memory issues 
  • Sleep disturbances 
  • Fibromyalgia
  • Muscle pain

What is the tool used to diagnose serotonin deficiency?

Neurotransmitter testing for experiencing pain and assessing the pain receptors and blood testing that can help determine serotonin deficiency. Still, there is no concrete diagnosis towards fibromyalgia and serotonin deficiency.  

What treatment of serotonin deficiency?

Drugs that raise serotonin levels, precisely the serotonin reuptake inhibitors like Prozac, Zoloft, Paxil, and Lexapro, are aimed to keep more serotonin in circulation.11

What effects does a high serotonin level cause?

A high serotonin level is due to taking two or more serotonergic medications that raise serotonin levels or using a single overdose of a serotonergic drug, leading to a dangerous condition called serotonin syndrome. 

Drugs and supplements that could potentially cause serotonin syndrome12

 Serotonin syndrome is associated with factors like:12

  • Agitation
  • Confusion
  • Anxiety
  • Muscle rigidity and stiffness, especially in the legs
  • Profuse sweating
  • Fluctuating blood pressure and rapid heart rate 
  • Difficulty in balance

Serotonin syndrome is a fatal syndrome that needs emergency medical help as soon as possible, and it resolves within a few days. 

How is serotonin syndrome diagnosed?

Clinical factors are acknowledged by consulting the medication history, signs and symptoms, and a physical examination. Some laboratory findings may reveal serotonin syndrome as elevated white blood cells in the complete blood count, elevated creatine phosphokinase, indicating muscle injury, and a decreased bicarbonate level which indicates acidosis in the body.13 


Treatment of serotonin syndrome includes stopping the problematic drug and taking benzodiazepines to reduce agitation and lower blood pressure and heart rate. 

In severe cases,  hospitalisation can be a solution, including oxygen administration, monitoring the heart, intravenous fluid administration, and the administration of an antidote for serotonin called cyproheptadine.12,13

Prevention is better than cure, so it is good to be cautious when taking a drug, avoid taking too many serotonin-elevating drugs, and communicate with your healthcare provider if you feel any symptoms to treat when they are still mild. 


Serotonin is the natural mood booster and if a low level of serotonin causes the serotonin syndrome effect on the body, we will know that we need to take care of our mental health. 

Fibromyalgia is a disease that requires more investigation, so it is always important to monitor any symptoms to get earlier treatment and improve quality of life. 


  1. Watson S. Serotonin: The natural mood booster [Internet]. Harvard Health. 2021 [cited 2023 Jun 19]. Available from:
  2. Wicksell RK, Kemani M, Jensen K, Kosek E, Kadetoff D, Sorjonen K, et al. Acceptance and commitment therapy for fibromyalgia: a randomized controlled trial. Eur J Pain. 2013 Apr;17(4):599–611.
  3. Makrani AH, Afshari M, Ghajar M, Forooghi Z, Moosazadeh M. Vitamin D, and fibromyalgia: a meta-analysis. Korean J Pain [Internet]. 2017 Oct [cited 2023 Jun 25];30(4):250–7. Available from:
  4. Amin OA, Abouzeid SM, Ali SA, Amin BA, Alswat KA. Clinical association of vitamin D and serotonin levels among patients with fibromyalgia syndrome. Neuropsychiatr Dis Treat [Internet]. 2019 May 27 [cited 2023 Jun 25];15:1421–6. Available from:
  5. Simon LV, Keenaghan M. Serotonin syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Jun 28]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Noran Kotaem

Bachelor's degree, Dentistry, The British University in Egypt

Noran is a dentist and a teaching assistant at the Faculty of Dentistry in the British university in Egypt. Passionate about research, reading and writing in the fields of medicine, nutrition and lifestyle. Keen to learn more about evidence based scientific research and writing. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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