This condition is benign (when isolated) and does not cause pain or affect the thumb with the trait negatively.

If a person has the genes for this condition, it might present bilaterally, unilaterally, or on none of the thumbs.

The signs of this trait are having a thumb with a distal phalange that is able to bend backwards beyond the normal range of motion.

The exact cause of isolated hitchhiker's thumb is not known, it is thought to be inherited in an autosomal recessive manner.

[4] However, this trait is often a symptom of an underlying condition, such as It does not need treatment.