Radius (forearm bone)

What it means

The radius is one of the two long bones of the forearm, running from the elbow down to the wrist on the thumb side. It is the bone that forms most of the wrist joint, so a great deal of the hand's load passes through it. The radius also lets you turn your palm up and down, swivelling around its partner bone as you rotate your forearm. Its lower end, near the wrist, is broad and is a frequent focus of reports.

Why it appears on a CT, MRI or X-ray report

Radiologists name the radius to point to that forearm bone, very often at the wrist end. A fall onto an outstretched hand commonly breaks the radius just above the wrist, so this is one of the most frequently described fractures of all. Reports may note where a break sits, how well the pieces line up, whether it extends into the wrist joint, or signs of healing. Naming the radius simply marks the bone involved.

What it usually means

In most reports, the radius is named just to locate a finding. On its own the word means nothing is wrong; the bone is often described as normal or intact. When a finding is noted, it is most often a wrist-end fracture after a fall, one of the commonest breaks at any age, particularly in children and older adults. Many of these heal well in a cast once any displaced pieces are gently realigned, while some that disturb the joint surface or stay out of line need a specialist or a procedure. Old healed breaks and mild wear at the wrist are also common and usually need no action. The Latin name itself is ordinary. What matters is the description beside it, particularly alignment, which guides treatment.

When to follow up

The name on its own needs no action. What deserves attention is whatever the report says, such as a fracture, displaced or angled pieces, or a break extending into the wrist joint. If your report mentions these, ask your doctor whether you need a cast, realignment, or an orthopaedic specialist, especially if the wrist looks crooked or is very swollen. Seek prompt care for a deformed wrist, severe pain, or numbness and tingling in the hand.

A plain-language way to picture it

Hold your arm out with the palm up: the radius is the forearm bone on the thumb side, the one that does most of the work where your wrist meets your hand. When you turn your palm down, it rolls over its neighbour like one log rotating across another. Because it carries the wrist's load, it is the bone that usually takes the hit when you fall onto your hand.