The revelations come in the midst of the National Year of Reading in Wales, which is being co-ordinated by the Welsh Books Council.
And they follow the growing use of reading therapy to help people who are suffering from mild forms of depression.
The scheme has also been extended across parts of Wales to children with emotional and psychological problems and their families, reports Madeleine Brindley for Western Mail.
GPs, health visitors and school nurses are able to recommend self-help books, which can in turn help people to understand and manage their conditions. Wales led the way in the UK by setting up a nationwide book prescriptions scheme in 2005 after it was piloted in Cardiff.
It has since been copied across the UK with so-called bibliotherapists working with health professionals who prescribe high quality self-help books, which have similar treatments to those they would receive in counselling.
But simply reading a book for pleasure also has its health benefits as it can help people to take their minds off everyday problems.
A few minutes reading is thought to have a therapeutic and long-lasting effect.
Dr Tony Jewell, Wales' chief medical officer, said: "Reading can be helpful in understanding all sorts of health problems, giving people information and tips on how to help manage their illness better.
"For example in the field of mental illness, if you have problems then there are books on all types of issues from depression and anxiety to anger management that can be obtained to give advice and support.
"In Wales a range that has been recommended by experts in their field can even be prescribed by your GP and lent free from the local library."
And NHS Direct advises that: "Reading is beneficial for both children and adults. It can help you to cope with stress and anxiety, and provide a form of relaxation and escapism.
"It is also a great brain tool, helping people of all ages to learn and develop important life skills, in terms of education, self improvement, positive life choices and all round wellbeing.
"Reading is great for adults too - settling down with a good book or a favourite magazine is a great way to unwind at the end of a stressful day, and enjoy some 'you time'.
"It can take your mind off your worries and woes, and often a bit of time-out helps you to put things in perspective and cope better."
It is thought that all types of books can help people relax including novels, fiction, non-fiction, biographies as well as self-help, self-improvement, health, motivational and educational books.
The National Year of Reading in Wales brings together people from all across Wales to share the joy of reading. A wide range of activities have already been held as part of the year ranging from locally arranged reading groups through to the Give a Book Week and Reading Communities initiatives.