Meanwhile, it’s extremely common for non-life-threatening low back pain to be alarmingly severe and persistent — to have a loud bark! Your doctor may not appreciate how true this is, and may over-react to all persistent low back pain, even without other red flags. In most cases, you shouldn’t let them scare you. Being “freaked out” about persistent back pain is the real threat: it can make low back pain much worse, and much more likely to last even longer (a tragic irony).
Low back pain (LBP) is a common disorder involving the muscles, nerves, and bones of the back.[4] Pain can vary from a dull constant ache to a sudden sharp feeling.[4] Low back pain may be classified by duration as acute (pain lasting less than 6 weeks), sub-chronic (6 to 12 weeks), or chronic (more than 12 weeks).[3] The condition may be further classified by the underlying cause as either mechanical, non-mechanical, or referred pain.[5] The symptoms of low back pain usually improve within a few weeks from the time they start, with 40–90% of people completely better by six weeks.[2]
In most episodes of low back pain, a specific underlying cause is not identified or even looked for, with the pain believed to be due to mechanical problems such as muscle or joint strain.[1][4] If the pain does not go away with conservative treatment or if it is accompanied by "red flags" such as unexplained weight loss, fever, or significant problems with feeling or movement, further testing may be needed to look for a serious underlying problem.[5] In most cases, imaging tools such as X-ray computed tomography are not useful and carry their own risks.[9][10] Despite this, the use of imaging in low back pain has increased.[11] Some low back pain is caused by damaged intervertebral discs, and the straight leg raise test is useful to identify this cause.[5] In those with chronic pain, the pain processing system may malfunction, causing large amounts of pain in response to non-serious events.[12]
Doing the bridge exercise in the morning gets your muscles working, activated, and engaged and will help support you the rest of the day, says Humphrey. Lie on your back with your legs bent and your feet flat on the floor, hip-width apart. Press down through your ankles and raise your buttocks off the floor while you tighten your abdominal muscles. Keep your knees aligned with your ankles and aim for a straight line from knees to shoulders, being sure not to arch your back; hold this position for three to five seconds and then slowly lower your buttocks back to the floor. Start with one set of 10 and build up to two or three sets.
Of course, you know what it feels like to have a tight muscle. But tight hips aren't just uncomfortable—they can lead to all sorts of other aches and pains, especially in the lower back. "People focus on the hips and say their hips are tight, but we don't always think about the fact that the lower back connects to our legs at the hip," Charlee Atkins, C.S.C.S., instructor at Soul Annex in New York City and creator of Le Stretch class, tells SELF. Tight hip flexors make it harder for your pelvis to rotate properly, which can cause your lower back to overcompensate, "and this can be a setup for lower-back injury," Teo Mendez, M.D., an orthopedic surgeon at NY Orthopedics who focuses on operative and non-operative management of sports-related injuries, musculoskeletal injuries, and arthritis, tells SELF.
Swimming is a low impact form of exercise that can help to relieve the pressure on your joints. It’s thought that water aerobics may help to reduce the impact on your joints by up to 75%!2  Be careful though; start with a beginner’s class and always do only what you’re comfortable with – try to avoid over-exercising or pushing your muscles too far!
But how can you tell? It can be tricky. This is a concise, readable guide to symptoms that need better-safe-than-sorry investigation with your doctor. (It’s basically just a plain English version of clinical guidelines for doctors.9) In other words, this article explains the difference between “dangerous” and “just painful” as clearly as possible. Tables, checklists, and examples ahead.
Some of these red flags are much less red than others, especially depending on the circumstances. For instance, “weight loss” is common and often the sign of successful diet! (Well, at least temporarily successful, anyway. 😃) Obviously, if you know of a harmless reason why you have a red flag symptom, it isn’t really a red flag (duh!). But every single actual red flag — in combination with severe low back pain that’s been going on for several weeks — is definitely a good reason to get yourself checked out.