Introduction

Pain is a sensation we have all heard about and experienced in our lifetime. It is defined as an unpleasant sensory and emotional sensation that is a result of actual tissue damage. The physical receptors in our body called nociceptors detect pain and send signals to the brain to cause a response. For example, if you touch a hot object with your hand, the nociceptors detect the pain and communicate this to the brain, the brain will then create a protective response pathway to trigger a reflex to move your hand away. The body and the brain are therefore linked, physical pain often creates a low mental mood and alternatively, your mind and emotions can also create a pain sensation regardless of any physical source. This type of pain is referred to as psychogenic.¹

What is psychogenic pain? 

Psychogenic Pain is pain that is experienced without direct injury, neural damage or physical explanation but is a result of a combination of psychological, emotional or social factors, this often makes it more difficult to treat.² Even without external stimuli, pain produced in the mind can be processed in the same way as physical pain, causing a significant impact on the quality of an individual's life..¹ The term ‘psychogenic’ is an outdated term in clinical practice today, but it is still important as it has influenced pain to be approached more holistically.³

Biological mechanism of psychogenic pain? 

So the question we seek to answer when it comes to psychogenic pain, is how do the nociceptors get activated? 

1. The first way is by amplification of how pain is perceived from the signals the brain sends to the body which are then sent back to the brain which is known as retrograde signalling²
2. The second way in which nociceptors are activated is in the aftermath of prolonged muscle tension which is seen in many psychological disorders. The muscle tension increases the synthesis of algogens which are found in the muscle tissue that produce pain sensation and sensitise nociceptors terminals making them sensitive to pain²
3. Thirdly, the activation of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis in periods of psychological conflict can increase and create further nociceptor activation and excitation²

Cause of psychogenic pain? 

Having understood the biological mechanism of psychogenic pain, we can look further into the multiple causes of psychogenic pain, which rely on the individual's environment, mental health, and past trauma or social factors.³ 

Environment

People are significantly impacted by their environment, and this can control, to some extent, their pain reaction. The main example of this is in the influence of highly stressful environments that can influence individuals to feel a heightened sense of pain.³ 

Why do fear and stress cause psychogenic pain? 

Stress is a state of emotional worry or physical tension as a result of a difficult pressure. This reaction can cause individuals to increase their perception of pain or experience it for longer periods of time.

When you encounter a stressful event or thought, an area of the brain called the amygdala signals to the hypothalamus to release corticotropin-releasing hormone (CRH), which causes the anterior pituitary gland to secrete adrenocorticotropic hormone, which triggers cortisol release from the adrenal glands.⁵

Cortisol is an anti-inflammatory hormone which is crucial in a short-term stress response but if you feel stressed for long periods of time, the body’s sympathetic system will be continued to be activated and cortisol will be continuously be secreted, leading to increased pain sensitization.⁴ 

In a similar way, fear is another emotion that can create psychogenic pain. In situations where a patient experiences pain as a result of direct tissue injury they may also develop a fear response. This may lead to fear avoidance behaviour whereby the activity which caused the pain is avoided and the individual focuses on the worst possible outcome known as catastrophization. This behaviour pattern creates an association with fear and pain so that even non-harmful experiences are associated with pain. 

Although stress and fear can lead to psychogenic pain it doesn’t work alone, the pain is due to a combination of genetics and the environment of an individual.⁴ 

Symptoms of psychogenic pain due to stress/ fear: 

• Muscle tension often in the neck, back or shoulders
• In severe cases, pelvic/ abdominal pain 
• Hypervigilance to normal pain response⁵

Individuals with personality traits that experience higher levels of stress and anxiety such as obsessive compulsive personality disorder are also more likely to experience psychogenic pain.⁴ 

Mental state

Pain is often felt more intensely without stimuli during periods of low mood and psychological disorders which can include anxiety, depression and even bipolar. The way in which emotions and thoughts are regulated plays a part in the way in which pain is interpreted by the brain.⁵

Why does anxiety and depression cause psychogenic pain? 

Both anxiety and depression are disorders which cause a change in neurotransmitters called serotonin or norepinephrine, which can cause an increased sensation to painful stimuli. Anxiety is the emotion characterised by uneasiness and tense worry; similar to fear and stress, anxiety can stimulate the sympathetic system and cortisol release, contributing to increased pain perception.⁵

Depression is another condition associated with the development of psychogenic pain and it is a term used to describe a state of low mood, loss of pleasure and low self-worth.⁶ For both anxiety and depression there is a physiological connection with pain, because the area for processing anxiety and depression by the brain also interacts with the area which generates emotional and physical pain known as the somatosensory cortex; this concept is referred to as the pain matrix.⁷

This has been evidenced in studies using equipment called Functional magnetic resonance imaging (fMRI) which maps areas of brain activity by measuring changes in blood flow. It is shown that there is a greater level of brain activity in areas responsible for pain in patients with social anxiety disorders.⁵

Symptoms of psychogenic pain due to anxiety/depression 

• Chronic joint, limb and back pain
• Gastrointestinal problems
• Tiredness/ sleep disturbances
• Changes in psychomotor activity
• Headaches⁸

Social factors 

An individual’s social background, upbringing and traumatic experiences can affect how they experience pain.³

Past traumatic experiences 

Trauma can increase the activity of the nervous system and often leads to a state of hyperarousal. Hyperarousal is a combination of anxiety and hypervigilance that forms part of a post traumatic stress disorder response (PTSD). Like other anxiety disorders, it can physically lead to chronic muscle tension in joints creating pain for the individual. It also causes the prolonged secretion of cortisol leading to increased pain sensitivity.

Trauma also causes patients to exercise much less than usual and the lack of movement creates psychogenic muscle and body pain.⁸

Symptoms of psychogenic pain due to PTSD 

• Widespread chronic pain 
• Headaches 
• Abdominal pain 
• Muscle pain 
• Non specific pain ⁹

Other factors of psychogenic pain symptoms 

Although we have outlined the common symptom of psychogenic pain, these symptoms all share the following in common: 

• Pain is not caused by a injury or physical medical condition 
• Pain may be associated with other psychological symptoms 
• Pain is not seen with other physical/ physiological changes 
• Pain may worsen with increased anxiety or changes in mood 
• Pain is inconsistent and may not always be relieved by traditional medication¹

Summary 

Nowadays, the term psychogenic pain is rarely used as all pain is approached from a wider perspective so that there isn’t the so-called ‘all in your head’ stigma attached to this pain, instead the term ‘nociplastic’ pain is used. This is why understanding and sharing information regarding this type of pain is so important so that patients do not feel isolated or frustrated with their condition.¹⁰ 

Exploring the connection between the mind and the body helps to pinpoint that pain can be a result of fear, stress, anxiety, depression and past trauma, and knowledge of these psychological factors can help to understand their associated symptoms such as muscle, joint, back pain, headaches, gastrointestinal problems and non-specific pain. It is important for patients with psychogenic pain to reach out to healthcare professionals for treatment including painkillers, psychotherapy or even antidepressants and to not feel misunderstood with their condition.³