The phrase "long haul" originated around 1873 as a way to determine the cost of transporting goods and people great distances by rail. The longer the haul, the less was charged per mile.

That's the opposite of what many survivors of COVID-19 mean when they use the phrase to describe residual health challenges after recovering from the virus.

One "long haul" effect of COVID-19 that doctors have been struggling to understand is the persistence of chronic pain or numbness in hands and feet.

A new study published in the journal Radiology suggests two causes of this lingering condition. The body's own immune response to the virus may trigger widespread inflammation that attacks the nerves, or the sensations may be caused by reaction to blood thinners.

In the latter case, blood collects outside of the blood vessels, forming a hematoma, and puts pressure on the nerves.

Knowing these potential causes of symptoms can allow doctors to more accurately determine which treatments will be most effective.

The researchers from Northwestern University Feinberg School of Medicine also stress the importance of knowing where in the body the pain originates. That's possible by using advanced imaging technology.

They suggest anyone with such post-COVID nerve sensations see about undergoing very high-resolution ultrasound and magnetic resonance imaging neurography (MRI of peripheral nerves). Then your doctors will have a shot at knowing the cause of the symptoms and where the sensations originate from.

Don't suffer in silence. Make sure your doctors know about these new insights and approaches to treating COVID-19-related nerve damage.