The neck and the shoulders are quite a complex series of joints and muscles it's easy to have things go wrong. To add to that, seemingly unrelated factors such as your diet, your breathing patterns, the strength in your belly and intestines, can also contribute to this massive issue that is experienced by so many people on a daily basis.
You may spend a fortune on massage, chiropractic work, acupuncture, yoga - or whatever your choice of treatment may be, but all of this can be a waste of time if you are not addressing each of the following issues (which are all for free):
Food is a huge culprit to tension and stress around your neck and shoulders. Consider that food has different energies within it and affects the body in a variety of different ways. For example, salt has a downward energy and can contract things in the body, brings us heat and moves down to the lower body. Sugar, on the other hand, has a rising energy, expands everything and moves to the upper body. In fact sugar has so much rising energy that it often rises so fast to the upper body that it causes massive problems in the neck and shoulders causing tightness, tension and even headaches. Sugar, by itself especially causes tightness in the left side of the body, and when you wake up one morning and can't turn your head, this is NOT because you 'slept wrong', but because of the sugar consumption yesterday or a day or two ago! "Yes", it may be true that you slept 'wrong', but you did so as the sugar contorts your body into that shape to start with!
Alcohol also plays havoc with your upper body. It will mainly affect the right side of your body, but also gives you lots of tension in the upper back between your shoulder blades. Notice this the next time you have a big night. Unfortunately, if you drink everyday, you may not notice the difference as you are probably tight up there all the time. The body is basically like a map for our organs and meridians and the area between your shoulder blades relates to the heart. Did you know alcohol puts a huge amount of pressure on your heart? If you want further proof of this try walking up a steep hill or some stairs after you've had a few drinks and notice how much (more than usual) your heart starts to THUMP. This will even be the case the day after you've had a few drinks.