Back pain can be caused by a variety of conditions—while osteoporosis and arthritis are traditionally orthopedic conditions that you hear a lot about, there are other potential causes of your pain of which you should be aware.

Here are four potential orthopedic conditions that you should know about.

Sciatica

You've probably heard someone say something along the lines of "my sciatica is acting up" at one point or another—but what does this condition actually entail? First of all, sciatica is more of a symptom than it is an out-and-out condition. It's often a sign of other conditions, such as the ones below. It will typically involve a consistent pain, usually at its worst when a person is sitting, in the leg and rear. That achiness or feeling of weakness can make rising from a seated position uncomfortable. Pain emanating through the sciatic nerve can cause pain from the lower back all the way down one side of your lower body to your feet.

Bonus Fact: While it's more common among middle-aged individuals, younger people aren't immune sciatic pain—people as young as their 20s can experience this type of nerve pain. It affects nearly half of the population at some point in their lives, according to the New England Journal of Medicine. In young people, sciatica is most commonly caused by disc herniation.

Degenerative Disc Disease

The style of the condition can vary, but generally speaking, degenerative disc disease (or "DDD") is caused by inflammation of an aging or "degenerating" disc in the spine. Perhaps the most painful symptom of the condition is the reflex spasm that often occurs when your body is attempting to stabilize its inflamed spine. While it may not always be clear that DDD is evident right away, back or neck pain that can last several days or that becomes ongoing can be an early warning sign. Bending over and picking up objects can also spur the related pain.

Bonus Fact: This condition primarily affects people as they age (hence, "degenerative")—according to the Chicago Institute of Neurosurgery and Neuroresearch, by 50 years old, more than 80 percent of people will start to experience DDD. (But not all will have symptoms at first or at all.)

SI Joint Dysfunction

The sacroiliac joint, or "SI joint," is situated at the base of your lumbar—essentially in the vicinity of your tailbone. It connects your spine to your pelvis. When this joint is irritated or inflamed, it can cause pain in your lumbar and one or both of your legs. Dysfunction can set it in from several causes, but two common ones are overdoing lower back movement or lack of activity in your SI joint. Injections are often considered a good way to determine an SI joint dysfunction is present.

Bonus Fact: While SI joint dysfunction can affect anyone, it's most common in younger to middle-aged females. This is due to pelvic size and hormonal differences between men and women and can be a condition spurred during pregnancy.

Spondylolisthesis

When young adults experience lumbar and/or leg pain, one common cause is a slippage of spinal vertebra, causing it to become uneven with the vertebra below it. This is called spondylolisthesis—it's a condition that can have similar symptoms to other orthopedic conditions but is typically caused by an impact or injury—or spondylolysis. This type of injury can also be quite common among particularly active teenagers—especially student athletes.

Bonus Fact: According to the American Journal of Sports Medicine, spondylolysis injuries appear to be most common in athletes with lower-back-heavy movement, such as winter sports, rowing and boxing.