You Woke Up With a Sore Lower Back - Why? Because of the Increased Pressure in the Discs At Night

spinal stenosis

A significant number of people have the experience of going to bed every night with a normal back and waking up in the morning with a sore one. Why is that? Why is morning low back soreness so common, and what causes it? As will be discussed in this article, the phenomenon is not that rare, and is caused by changes in the spine and the discs overnight.

When people go to bed, their spines actually increase in length. This is a result of the pressure in the discs in between the vertebrae changing. In fact, one study done in 1984 showed that people's sitting height can dramatically decrease throughout the day -- up to 19 millimeters in some cases. This is due to the discs losing some of the fluid that built up during sleep.

A spine that has spent the night horizontal and building up fluid is a spine that has lost some of its flexibility, as well. This is why people may wake up and feel that their lower back is sore and they just feel "stiff" upon rising from bed. Especially the ability to bend forward and flex the spine can be compromised after a night of sleep. The discs have expanded during the course of the night, built up fluid, and the spine has become more resistant to such bending.

The good news is that this soreness does not usually last all day, and there are actions that people can take to reduce their low back soreness in the morning. In fact, due to the changes in the disc pressure during the night, it is quite important for some people who are especially at risk of injuring or re-injuring their backs to take precautions in the morning to ensure their spinal health throughout the day.

The most important action to take is to avoid much forward bending for the first hour upon waking. The discs of the spine will lose about 90% of the pressure and extra height they have gained during the night in the first hour after getting out of bed. Because of the increased pressure during this first hour, though, doing any kind of spinal flexing or exercises that involve the back may be best avoided until later in the day.

People who are currently suffering from a back injury or who are in physical therapy for rehabilitation of an injury are frequently prescribed various spine exercises. While these can help with the healing process, if they involve a lot of flexing or extension of the spine, it may be best not to do these right after getting up. Exercises to increase stability and muscle endurance can help, but not if they exacerbate symptoms in the mornings.

Finally, the best advice may just be to stay aware that the spine increases in length during the night and the discs increase in pressure. But after the first hour or two after rising, most people's sore backs may begin to feel normal again. It is most important not to round the back or flex too much in morning, as just this simple avoidance of full flexion can help reduce the pain of a sore lower back.