Pain

Pain is a complex signal from your body that something may be wrong, affecting millions of people worldwide through physical discomfort and emotional challenges that can disrupt daily life.

Table of contents

• What is pain?
• Patterns and types of pain
• How the body processes pain
• Effects of pain on daily life
• Diagnosing pain
• Treatment approaches
• Self-management strategies

What is pain?

Pain is an unpleasant sensory and emotional experience that serves as a signal in your nervous system that something may be wrong^[1]. No two people feel pain the same way, even if the reasons for their pain are alike. Pain is a highly personal experience, and a person’s report of their own pain is the best measure^[1].

Pain can include pricking, tingling, stinging, burning, shooting, aching, or electric sensations^[1]. It may feel mild or severe. You may experience pain in one area of your body, such as your back, abdomen, chest, or pelvis, or it may be felt all over^[2]. Pain can be sharp or dull, and it may come and go, or it may be constant^[2].

Pain is among the most important signals our body gives to help us survive. It can alert us to harmful changes in the body, like cancer, or help us learn to avoid something harmful, like touching a hot stove. In this way, some forms of pain keep us safe^[1]. However, in other cases, pain exists or continues without any known cause or benefit^[1].

Patterns and types of pain

There are three primary patterns of pain, which are named based on how long the pain lasts and its frequency^[1].

Acute pain starts suddenly and ends when its cause is treated or healed^[1]. The feeling of acute pain is usually sharp because it tends to act as a warning signal about a threat to the body from an injury, disease, overuse, or other environmental stress. Common causes for acute pain are strained muscles, broken bones, dental work, surgery, childbirth, infections, and burns^[1]. This type of pain usually goes away when the cause is treated or healed, though sometimes it can turn into chronic pain^[2].

Episodic pain happens from time to time and may be at irregular intervals^[1]. It may be associated with a long-term medical condition, like sickle cell disease. Painful periods and chronic migraine are examples of episodic pain. It can happen out of nowhere or may be caused by known triggers^[1].

Chronic pain lasts for longer than three months or the expected healing time^[1]. In some cases, an acute pain condition might persist and become chronic pain. In other cases, chronic pain happens for no known reason. People might experience one or more chronic pain conditions, or chronic and acute pain, at the same time^[1]. Chronic pain can affect all aspects of daily life, including your mood and relationships^[2].

Pain can also be put into categories based on its most likely source. In many cases, pain fits into more than one of these categories^[1]:

• Nociceptive pain describes pain that is caused by tissue damage or inflammation. The sensation can be sharp, pricking, dull, or aching, depending on what caused the damage or inflammation. Examples of nociceptive pain are pain from a paper cut, an infection, a broken bone, or osteoarthritis^[1].
• Neuropathic pain describes pain that is caused by nerve damage due to an injury or disease^[1]. You can experience neuropathic pain from injuries or illness that affect the spinal cord and brain (for example, a slipped disc in your spine) or the peripheral nervous system (the nerves throughout the rest of your body)^[5]. This kind of pain often feels similar to burning, shooting, or stabbing^[5].
• Nociplastic pain is caused by changes in how your nervous system processes pain^[2].
• Inflammatory pain happens when your immune system activates in response to injury or infection. In addition to causing redness or swelling, it can also make you more sensitive to feelings of pain^[5].

How the body processes pain

When you are in pain, it’s because your nervous system thinks that a part of your body is injured or in danger of getting injured^[5]. You don’t become aware of pain until your brain processes it^[5].

The body has pain receptors that are attached to nerve fibers. When a part of your body is injured, special pain receptors from that area release chemicals called neurotransmitters, which are chemical messengers in the nervous system that facilitate communication between nerve cells^[7]. These messages travel along nerves to the spinal cord and eventually to the brain^[5].

The messages are sent to a part of the brain called the thalamus, which then transmits the pain signal to other areas of the brain to be processed^[7]. Once the brain has received and interpreted the pain message, it coordinates an appropriate response^[7]. Your brain sends messages back to your body to react. Depending on the situation, this could mean rapidly triggering the muscles in your body to move you away from whatever is causing your pain. This reaction can feel instantaneous^[5].

Sometimes the spinal cord sends an immediate signal back to the muscles to make them contract. This moves the affected body part away from the source of danger or harm. This is a reflex reaction that prevents further damage occurring. It happens before you are even aware that you are in pain^[6].

If you are injured, your brain might also release natural painkillers called endorphins or tell your immune system to start healing the injury^[5]. The brain can signal the release of natural painkillers known as endorphins. Alternately, the brain can direct the release of neurotransmitters that enhance pain or hormones that stimulate the immune system to respond to an injury^[7]. Recent research has shown that people possess differing amounts of these neurotransmitters, possibly explaining why some people experience pain more intensely than others^[7].

Some areas of the body have more pain receptors than others. For example, the skin has lots of receptors so it is easy to tell the exact location and type of pain. There are far fewer receptors in the gut, so it is harder to pinpoint the precise location of a stomach ache^[6].

When pain continues for a long time—such as during a long illness or after a serious injury—it can cause changes to your nervous system, which make you more sensitive to pain. This means that certain stimuli make you feel pain more quickly, and the pain can be more intense and last longer^[5].

Effects of pain on daily life

Pain is the most common reason for physician consultation in most developed countries^[4]. It can make it harder to do necessary tasks, work, and enjoy activities^[1]. Pain can affect a person’s mood, relationships, movement, and all aspects of daily life^[1].

People in pain experience impaired concentration, working memory, mental flexibility, problem solving and information processing speed, and are more likely to experience irritability, depression, and anxiety^[4]. Pain can make you tired, anxious, depressed and grumpy. This can make the pain even worse, making you fall into a downward spiral^[13].

Your experience of pain is influenced by a complex set of factors that are unique to you, including your genes and biology, past experiences, emotions, and environment^[5]. Anxiety, depression, or sleep problems can make pain more unpleasant than it would normally be^[8]. Studies suggest that a person’s emotional wellbeing can impact the experience of pain^[6].

Many people with long-term pain find it difficult to sleep at night. Sleep deprivation can also make pain worse^[13].

Diagnosing pain

You are the only one who knows how your pain feels. Your provider can best measure your pain by how you report it^[2]. A thorough medical history and physical exam are the most important tools to determine the cause of your pain and should assess how the pain affects your function and quality of life^[20].

Your healthcare provider may ask you^[2]:

• Where is the pain in your body?
• How long have you had the pain?
• How does the pain feel, such as stinging, burning, or sharp?
• How often do you have pain?
• When do you feel pain, such as in the morning, evening, or all the time?
• What relieves the pain?
• How does pain affect your daily life?
• Is the pain mild, moderate, or severe?
• To rate the pain on a scale.

If the cause of your pain is unknown, your provider may also do a physical exam and order blood tests or other medical tests to help find the cause^[2]. Doctors may recommend diagnostic imaging tests such as X-ray or MRI to confirm the diagnosis and guide treatment^[20].

Treatment approaches

Pain is not always curable, but there are many ways to manage and treat it. Treatment depends on the cause and type of pain^[2]. Because people feel pain differently, there’s no single treatment that will work for everyone^[5]. Understanding the cause and learning effective ways to cope with your pain can improve your quality of life^[6].

Key pain management strategies include^[6]:

• Pain medicines
• Physical therapies (such as heat or cold packs, massage, hydrotherapy and exercise)
• Psychological therapies (such as cognitive behavioural therapy, relaxation techniques and meditation)
• Mind and body techniques (such as acupuncture)
• Community support groups

Medications

Treatments may include medicines, such as pain relievers^[2]. Simple pain medications are useful in 20% to 70% of cases^[4].

Milder forms of pain may be relieved by over-the-counter medications such as Tylenol (acetaminophen) or nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and naproxen^[17]. Both acetaminophen and NSAIDs relieve pain caused by muscle aches and stiffness, and additionally, NSAIDs reduce inflammation (swelling and irritation)^[17]. Topical pain relievers are also available, such as creams, lotions, or sprays that are applied to the skin in order to relieve pain and inflammation from sore muscles and arthritis^[17].

If over-the-counter drugs do not provide relief, your doctor may prescribe stronger medications, such as muscle relaxants, anti-anxiety drugs, antidepressants (like duloxetine for musculoskeletal pain), prescription NSAIDs such as celecoxib, or a short course of stronger painkillers^[17].

Antidepressant medications, particularly selective serotonin and norepinephrine reuptake inhibitors and tricyclic antidepressants, especially amitriptyline, have demonstrated efficacy in a variety of neuropathic pain conditions^[12]. These medications are indicated for other pathologies such as fibromyalgia and chronic musculoskeletal pain. Also, antidepressants are recommended as a prophylactic treatment for migraine and tension-type headaches^[12].

Opioids are the strongest pain medicines. They’re called opioids because they first came from the opium poppy^[8]. Opioids are good for relieving really bad pain, such as from a burn, broken bone, or cancer. But opioids can have serious side effects so doctors try not to use them for less severe problems^[8]. Common side effects include nausea, constipation, and itching. Many people die each year from accidental opioid overdose^[8].

Medical procedures

A limited number of steroid injections at the site of a joint problem can reduce swelling and inflammation^[17]. Techniques involving injections are commonly offered to help alleviate pain. Known as interventional therapy, these injections often deposit local anesthetics or cortisone into the area surrounding nerves or joints^[14].

Transcutaneous electrical nerve stimulation (TENS) applies a gentle electrical current to your skin through a small sticky pad. The current tingles but doesn’t feel like a shock. It won’t eliminate pain, but it can help some people^[8].

Non-drug therapies

There are also non-drug treatments, such as acupuncture, physical therapy, and sometimes surgery^[2]. Psychological factors such as social support, cognitive behavioral therapy, excitement, or distraction can affect pain’s intensity or unpleasantness^[4].

Acupuncture involves stimulating acupuncture points. These are specific points on your body. The most common method involves inserting thin needles through the skin. Others include using pressure, electrical stimulation, and heat. Research suggests that acupuncture can help manage certain pain conditions^[16].

Biofeedback techniques use electronic devices to measure body functions such as breathing and heart rate. This teaches you to be more aware of your body functions so you can learn to control them^[16]. Biofeedback may help to control pain, including chronic headaches and back pain^[16].

Massage therapy is a treatment in which the soft tissues of the body are kneaded, rubbed, tapped, and stroked. Among other benefits, it may help people relax, and relieve stress and pain^[16].

Physical and occupational therapy will guide you through a series of exercises specific to your pain problem as well as show you safe and proper ways to perform daily living activities to avoid setbacks^[20]. Physical therapy uses techniques such as heat, cold, exercise, massage, and manipulation. It can help to control pain, condition muscles and restore strength^[6].

Meditation is a mind-body practice in which you focus your attention on something, such as an object, word, phrase, or breathing. This helps you to minimize distracting or stressful thoughts or feelings^[16]. Special mind techniques such as biofeedback, relaxation training, breathing techniques, and hypnosis can help you cope with pain^[8].

Practices that reduce stress and distract your mind from pain can significantly contribute to pain management. Relaxation can alleviate pain in a way akin to pain-relieving medicines^[21]. Meditation, tai chi, and yoga provide structured ways to calm your mind. These practices promote relaxation and have been shown to help manage chronic pain^[21].

Psychotherapy (talk therapy) uses methods such as discussion, listening, and counseling to treat mental and behavioral disorders. It can also help people who have pain, especially chronic pain, by teaching them coping skills to better deal with the stress that pain can cause, addressing negative thoughts and emotions that can make pain worse, and providing them with support^[16].

Self-management strategies

Depending on the cause of your pain and your symptoms, your provider may recommend lifestyle changes^[2]. Many non-drug treatments can help with pain^[16].

Exercise and movement

Simple, everyday activities like walking, swimming, gardening and dancing can ease some of the pain directly by blocking pain signals to the brain. Activity also helps lessen pain by stretching stiff and tense muscles, ligaments and joints^[13]. It’s natural to be hesitant if exercise is painful and you’re worried about doing more damage. But if you become more active gradually, it’s unlikely you’ll cause any damage or harm^[13].

Heat and cold therapy

Cold therapy can help numb a sore area, reducing pain. You can use a store-bought plastic gel pack, a bag of ice, or cool compresses for about 10 to 20 minutes at a time, 4 to 6 times per day. Protect your skin by placing a towel or other thin cloth between the ice and your skin^[21].

Heat can relieve tension and pain, especially in sore muscles. You can use heating pads, gel packs dipped in hot water, or a warm, moist towel. As with cold therapy, ensure there’s a barrier between the heat source and your skin and check frequently to avoid burning yourself. Hot baths and showers can also be soothing^[21].

Breathing and relaxation

Concentrating on your breathing when you’re in pain can help. When the pain is intense it’s very easy to start taking shallow, rapid breaths, which can make you feel dizzy, anxious or panicked. Instead, breathe slowly and deeply. This will help you to feel more in control and keep you relaxed and prevent any muscle tension or anxiety from making your pain worse^[13].

Deep breathing and other forms of meditation exist for the purpose of helping your body relax. As you breathe deeply, you can eventually loosen the muscles in your body, releasing tension and granting pain relief^[22].

Positive thinking

The messages you send to yourself have more power than you might think. Avoid negative thoughts like “I’m overwhelmed” or “I can’t cope with the pain.” Instead, focus on the progress you’ve made and remind yourself that you’re taking steps to deal with your pain and live the life you want^[21].

Sleep habits

The periods during which your body is at rest are extremely important for managing chronic pain and inflammation. It is vital that your body not only gets enough sleep but also quality sleep. This can be achieved by creating a routine and sticking to healthy habits before bed. Try to commit to a specific bedtime, reduce “screen time” while in bed, and cut back on alcohol, as all can improve the quality of your sleep^[22].

It’s important to try to stick to a normal sleep routine so you’ve got the best chance of sleeping through the night. Go to bed at the same time each evening, and get up at a regular time in the morning and avoid taking naps in the day^[13].

Healthy diet and weight management

If you eat healthier, you will eventually find that your body responds in tow, giving you more vitality. Obesity or a poor diet can add strain to your joints and muscles, sometimes aggravating conditions of chronic pain that you may already have. Eating healthier foods will only help decrease inflammation around your joints^[22].

Social support

Speaking about your pain with someone who understands can lift part of the burden. Online support groups for individuals living with chronic pain can offer comfort. Additionally, you can explore community centers, hospitals, or ask your doctor to refer you to in-person support groups^[21].

Do not let pain mean that you lose contact with people. Keeping in touch with friends and family is good for your health and can help you feel much better^[13].

Distraction

Shift your attention on to something else so the pain is not the only thing on your mind. Get stuck into an activity that you enjoy or find stimulating^[13]. Even simple distractions such as watching TV or listening to music can help shift your focus away from pain, reducing its perceived intensity^[21].