We have all experienced it in some sort of way, but what truly is pain? Why does our body perceive pain the way we do? Everyone experiences pain differently but scientifically we are all very similar in the way we feel and perceive pain. Pain can either be acute or chronic. Acute pain is the initial pain you feel when you are hurt or injured. Some people describe this pain as a "protective" pain because your body uses it to keep away from continued harm or danger. Acute pain could be as severe as a broken bone or even as small as a paper cut. Illnesses and diseases can also be considered acute. Acute pain typically resolves when your body recovers from whatever it may be. This type of pain typically lasts less than 3-6 months before it is considered chronic. Chronic pain on the other hand lasts much longer. The pain can last from months to years. Chronic pain can be from a clear cut injury or illness, can be a combination of multiple things attacking your body at once, or may not have a specific indicator for the pain. Acute pain is usually easier treated than chronic pain, but can become chronic pain if not treated properly.

These two pains can be broken down into 3 different causes of pain; nociceptive pain, neuropathic, or inflammatory. Nociceptive pain is caused by damage to body tissue. This is your typical acute pain. Examples of this are sprained ankles, muscle strain, contusions, burns, cuts, or stepping on a lego. Neuropathic pain is an injury or damage to the nervous system. This can be either in the central nervous system (brain and spinal cord) or peripheral nervous system (everywhere else in your body). Examples of this type of pain are herniated disc, sciatica, or carpal tunnel syndrome. Neuropathic pain is typically felt as a burning, shooting, or stabbing pain. The last cause of pain is inflammatory. Inflammatory is usually associated with the immune system and infection. The most common types are rheumatoid arthritis, psoriatic arthritis, Lupus, Gout, and Ankylosing Spondylitis. Inflammatory usually presents as redness and swelling.

Now that we know the difference between acute and chronic and the causes of pain, it is important to know how we experience and perceive pain. It happens fast, but you aren't aware of the pain until your brain processes all the information. For an easy example, let's say we touch a hot stove with our hand. When we place our hand on the stove, different and specific pain receptors release neurotransmitters which start the process of sending information to the brain. These neuroreceptors travel in an ascending neurological pathway that travels from the site of the injury to the brain. In this example the neurotransmitters travel from the hand, through the peripheral nervous system, to the central nervous system in the spinal cord, and up into the brain. The brain then receives the information, perceives the information and evaluates it, then decides how the body should respond. The brain can trigger an almost reflex like response which triggers the arm and hand to pull away from the stove. This happens so quick you don't even have to consciously think about it. The brain will also release the body's natural painkillers (endorphins) and start the healing process.

When we talk about treatment with patients the first question is usually ice or heat. The short answer is it depends. However, for the most part ice is better for acute pain and heat is better for chronic pain, but both can help both types of pain in different ways. The next time you are injured, you probably won't think about this entire process and tell your body how to respond. Your body has been doing it on its own for this long, it will most likely continue to protect you! However, the next time you are injured you will have an idea of what is going on in your body and can thank your nervous system for reacting the way it does to protect you.