Libido is mainly considered as the sexual drive or appetite. Overly high level libido and low level libido can affect 

High Libido : With a strong sexual appetite, it appears to be out of control interfering with the daily lives that there would be causes for concerns.

Low Libido : The disappearing sexual desire is quite common instead of the overly higher levels of libido having more powerful causes that can be treated easily to restore sexual interests.

Once you have identified the cause for low or high libido ,treatment becomes easier, and it involves other strategies such as increased physical activity and psychotherapy.