Spine Dragon site logo: Michael J H McCarthy, Consultant Spinal Surgeon

Patient Information: Why Hurt Does Not Mean Harm

The following information applies to patients with chronic pain in whom serious or sinister causes such as tumours, infections and trauma have been excluded.

The Different Types of Pain

It might seem a bit of a strange idea that something like your back can hurt without causing harm, but it does happen. The first thing to understand is that there are 2 types of pain. These are acute (short term) pain and chronic (long term) pain.

Acute pain is the kind you get if you tread on a drawing pin or stub your toe. This kind of pain is short term and has the purpose of telling your body that it is being injured. This kind of pain goes off quite quickly once the body is no longer being damaged.

Chronic pain is different. This is the kind of pain that continues on and on. It feels different to acute pain and unlike the acute pain it does not have a purpose. It is possible to have chronic pain without it meaning that the body is being damaged.

So how does this work? Well, for the pain signal to get to the brain it needs to pass along nerves from the back through the spinal cord to the brain. In the spinal cord there is a place where some of the pain signals need to pass across a joining nerve that goes in-between the nerves that continue on to the brain. This structure is called the pain gate. It is called the pain gate because the pain signal has to be above a certain strength to open the gate and continue to the brain. If the pain signals continue then gradually the pain gate gets easier and easier to open.

Because the pain gate becomes too easily opened, in time the signals that open the gate and cause pain need to be smaller and smaller until any signal at all will be received by the brain as pain. This is one of the reasons why when you move your back you get pain. Even when you move it only a very small amount far below the amount of movement a spine can make. The source of the original pain may well be gone but the nervous system has learnt the pain and keeps it going when there is no damage being done. This is how we can say hurt does not mean harm.

The Good News

The good news is that just as the pain gate can open it can also close. You can help the pain gate close by the way you react emotionally to the pain, by using medication to control the pain and by releasing the bodies own painkillers through exercise and relaxation.

In addition, periods of inactivity can result in pain and stiffness. This is normal. We all know that our joints ache after a long car journey or flight when we have been sitting still. Keeping things moving is the key.

Finally, the spinal muscles become deconditioned by inactivity and lack of use. Their main purpose is to help you stand upright. Long periods of rest and stooping forward to relieve any pain in your back may act only to worsen the situation. When you then come to use these muscles and stand upright they are not used to the work, fatigue rapidly and start to ache. Relieved only by rest and leaning forward the vicious cycle may then continue with increasingly shorter periods of pain free use. Hence the phrase “use it or lose it”. This is similar to the times when we were younger and played sports we weren’t used to or over did certain activities only to feel our legs aching the next day. When reconditioning your back muscles the pain may well get worse before it gets better. This does not mean you are doing yourself any harm. You will be using deconditioned weaker muscles that need time to re-strengthen and relearn their function.