As the rates of obesity and diabetes rise, more Americans also get fatty liver disease, a condition that's closely linked to both obesity and diabetes. In most cases, fatty liver disease doesn't cause many symptoms; in fact, most people discover they have it accidentally, when their doctor tells them a routine blood test showed abnormal liver function. If you just have a mild case, your back pain probably stems from something else. However, in very advanced cases, you may notice some back pain from fatty liver disease.
Fatty liver disease occurs when your liver cells hoard fat. Although it's not clear why this fat hoarding occurs, it's likely that insulin resistance -- part of the metabolic effects of being overweight and sedentary -- plays a major role. Up to 20 percent of Americans may have some fat in their livers, and up to 90 percent of obese people have the condition, according to the January 2011 "Harvard Health Letter." Fatty liver disease causes inflammation, both in your liver cells and in the surrounding tissue. Although it's unlikely in the earliest stages of the disease, such inflammation may lead to pain or discomfort in your abdomen, and it's possible that the discomfort may radiate to your back.
Not everyone with fatty liver disease sees the condition worsen; in fact, only about 5 to 10 percent of people who have been diagnosed with fatty liver disease go on to develop nonalcoholic steatohepatitis, a condition involving more serious liver inflammation, Harvard notes. From there, another small percentage of people -- up to 26 percent -- develop cirrhosis of the liver, in which they accumulate scar tissue that actually impairs their liver function. Cirrhosis can cause muscle pain and muscle loss, which you may feel in your back.
If your fatty liver disease has progressed to cirrhosis of the liver, you'll most likely notice many symptoms in addition to potential pain in your abdomen and back. Once your liver fails to function normally, digestive waste products can build up in your bloodstream and in effect poison your brain, leading to mental confusion, fatigue and disorientation. In addition, you may notice your skin becoming yellow, your palms may turn red, you may lose your appetite and shed pounds, and you may develop itching skin. Any of these symptoms should send you to your doctor for a complete checkup; only your doctor can determine whether you have advanced liver disease.
Back pain can develop from a number of different causes, including an injury, degenerative arthritis, nerve damage or damage from overuse during sports or work. If your fatty liver disease hasn't progressed to nonalcoholic steatohepatitis or outright cirrhosis, it's unlikely that your back pain stems from your condition. However, back pain sometimes can indicate another serious medical condition, such as cancer. Anytime you feel unusual back pain -- especially if you don't remember injuring your back or performing any task that might have stressed your back muscles -- consider seeing your physician to get it checked out.