I have this a lot. If you go to the top of the page and type in "Costochondritis" into the search section, you will be able to read heaps of posts about it. It has been extensively discussed by myself and other sufferers. I can give you information as a patient with this, but any information I personally give is not to be taken in a medical capacity.
It is most definitely not caused by draughts, or anything like that. It is an "internal" thing. The cartilage between the ribs gets inflamed and this causes the terrible pain that can occur. There are various forms of recommended treatment. I personally have my ribs and chest injected every so often, as this is the only way I get relief from pain as I cannot take NSAID's. Mine is as a result of other medical problems, but in some cases a traumatic event, like perhaps hitting your chest on the steering wheel of the car, can cause the inflammation to occur.
Here is a brief overview of the most common symptoms:-
Costochondritis is a syndrome of chest wall pain that is due to inflammation of the cartilage and bones in the area. It occurs when there is inflammation at the junction of the rib bone and breastbone (sternum). At this junction, there is cartilage joining these bones. This cartilage can become irritated and inflamed. Depending on the extent of the inflammation, this condition can be quite painful.
Most commonly the cause of costochondritis is classified as 'idiopathic,' or unknown. This means that there is no identifiable cause for the condition. This does not imply that idiopathic costochondritis is any less painful of a condition than if the cause can be identified. The most common symptom is pain over the front of the upper chest (the area of the sternum). Because of serious conditions, most importantly conditions related to heart problems, costochondritis should only be diagnosed after excluding other more serious problems. Always check these things out with your doctor to be on the safe side.
It is usually worsened by activity or exercise. One of the most common symptoms is that the pain is present when taking a deep breath. This stretches the inflamed cartilage and can cause horrendous pain. Often simply touching the area involved will be extremely painful for the patient.
Because of the many nerves that branch away from the chest, pain may be experienced in the shoulder or arms as well. There is another form which is called "Tietze's Syndrome" the pain with this though is accompanied by redness and/or swelling in the areas most tender which is not normal withCostochondritis.
As I said previously, you must check anything like this out with your doctor. I am only giving this information to you as a patient who has this problem.
Take care and have a Merry Christmas