[Disclaimer: I am not a doctor; I am not your doctor.]
|A trigger point in the upper arm can refer pain to the lower arm and hand. [Eric Vought]
|Gray's Anatomy, Brachial Artery (Public Domain)
Recall that the trigger point is a hardened bit of connective tissue. When the muscle tightens, the nerve and blood vessels between it and the muscle get trapped and pinched. This can reduce blood flow back from the hand and it can cause the nerve (which travels down to the hand) to register pain. It also tends to make you move your arm differently (even if you do not realize it), put tension on tendons, etc, and this affects the way you use your lower arm and hand, the way you grip, etc., causing pain or loss of function. The symptoms in your hand may not seem to make sense. But dealing with the trigger point in your arm may relieve the pain in your hand (or at least help).
The exact same process can happen in any of dozens of places in your body, causing a variety of unusual symptoms or (seemingly) inexplicable pain.
If you have trigger points like this, Travell and Simons´ "The Trigger Point Manual" may help your doctors understand how this works and will explain at a level that I could never do, especially in a blog. That book provides detailed diagrams of where trigger points occur, the satellite symptoms they may cause, and why. When I walk into an office and see a copy of this book, it makes me feel more comfortable that a practitioner will understand my condition. For yourself, Starlanyl and Copeland's "Fibromyalgia and Chronic Myofascial Pain Syndrome: A Survival Manual" is targeted at the individual sufferer who is trying to understand and cope with a bewildering condition. That book, given to me by a friend and fellow sufferer now gone, is what allowed me to get a handle on why my life was suddenly falling apart.
Learning to recognize where the pain is and why it happens helps to find relief. In the past, I would try to rub something into the hand or take an antiinflammatory. Now I know that often will not work. I find, personally, that concentrated capsaicin (from say, Capzasin-HP) on the trigger point will make my hand feel better. Capsaicin (from hot peppers) is absorbed through the skin and numbs the underlying nerve. It causes local pain (it burns a bit!) and skin irritation if I use it too much. But if I can use my hands more, it is a net win. If you have pain like this, learning more about it may help you find ways to live just a bit better. (Just wash your hands very well before you rub your face...) Massage and physical manipulation can also help or even correct trigger points. Just be careful and learn what you are doing (or find a good professional!) because doing the wrong thing can cause further harm. There are several old quack treatments for trigger points which did no good and left patients in agony, including "work hardening", surgery, and (some, older) trigger point injections.