Pain is complex.
Injuries can be complex.
Let use an example:
Patient A: Anterior shoulder pain when reaching overhead
Patient B: Anterior shoulder pain when reaching overhead
Is this enough information to decide how to treat these two patients? I would hope your answer is a resounding "OF COURSE NOT!"
Patient A is a 28 year old professional baseball pitcher.
Patient B is a 55 year old carpenter with 30 years of experience doing manual labor.
Ah, there's the difference. Now I know how to treat them. WRONG. Yes, this is all important information to understand what types of stresses each patient puts through their body, but it still does not tell us enough.
Even more information:
Patient A has full shoulder range of motion in all directions on his throwing shoulder, with the biggest limitations being in hip internal rotation.
Patient B has limited motion at his neck, shoulders, and hips and can't touch his toes.
By now you should see where I am going with this.
Your symptoms do not dictate your treatment. A thorough assessment of the entire body will tell us about how your body moves, where you are limited, and what strategy you use to get a given activity done.
Two people with similar symptoms can have very different explanations for their pain.
This is not to imply that all pain is due to limitations in range of motion, either. Social and environmental factors play a role in our symptoms, as well. Maybe patient A is stressed because he just broke up with his girlfriend, gave up 8 earned runs in a playoff game and got 2 hours of sleep. Maybe patient B just lost his job of 30 years and doesn't know how he is going to pay his mortgage.
Pain is complex. We need to appreciate the patient as a whole to understand what factors may be playing a role in their symptoms.
This is why when you say, "My back hurts, what should I do?" the answer is and always will be "it depends."