Rudraksh are beads that are naturally formed in the fruit of a tree. They are precious to Lord Shiva and are His jewels. They come with different facecs adding meaning to their existence according to their faced/mukhi.
I have studied the rudraksh as theory and also wearing the beads at different point of times with different elements(thread/silver chain/gold chain/copper wire) and have noted the different effect it has had on my being and hence can safely assume that these beads do not only contain within them a spiritual value but also have the potential to cure us of any ailment in our physical being as well.
Rudraksh and Bhadraksh:
One needs to be careful while selecting a rudraksh. Many people know the esoteric value of this bead and hence dupe people by making them out of wood and carving the faces on it. The original rudraksh can also be tampered with while selling them to unsuspecting people. Keeping a bhadraksh or a rudraksh that has been tampered with can bring reverse effects. Purity is thus an important aspect of a rudraksh, whatever the shape be!
One Mukhi:
It comes in mainly 2 shapes, crescent moon and round. The round is very rare and can be found only with the Kings in Nepal and are very costly indeed. The last I heard, it was being sold for Rs 1500000/-
Symbol Of : Lord Shiva, Godhood, Supreme Truth and Attainment of Eternity
Ruling Planet : Sun
Purpose: Enlightens super consciousness, gives power of concentration, changes mental structure, brings renunciationand natural inclination towards God. Brings peace and pleasure but balances one to remain neutral towards worldly gains. It also brings name and fame to the owner.
Cures: Headache, Heart Disease, Defect in the Right Eye.
One can wear it or keep it in the place of worship. Praying to the One Mukhi the first thing brings tremendous results.
My experience: I used to wear a one mukhi rudraksh in a gold chain. Undoubtedly, it brought me immense prosperity and luck. One day, the chain broke and ever since I did not wear the rudraksh again. Things did go haywire. However, today I have many one mukhi rudraksh beads, big and small kept in my space. I enjoy the power!

Two Mukhi:
Mainly used to heal relations and create a better understanding of others. It also heals emotions and brings insights into situations.
Symbol Of : Ardhanareshwar
Ruling Planet : Moon
Purpose : Heals relationships or malefics of the moon and it's phases, brings understanding amonsgst people, clears misunderstandings, the owner's family will also be benefited, off springs will bring luck, removes differences in relations.....husband-wife, teacher-student, father-son, friends, etc
Cures: Diseases Of the Left Eye, Intestine, Heart problems, Lung, Brain. I would say brain because it connects what we say and what we mean rather than letting our words and emotions lead us in parallel worlds.
My experience with the 2 mukhi has been unusual. I could never wear the bead for a long time and kept wanting to take it off everytime I felt fine. I think this puts great emphasis on the saying...Nothing in access. Maybe that's the amount of energy I needed on that particular day from the bead.
However, I did wear it with a combination of 6 mukhi beads (i.e. Four beads of 2 mukhi and two beads of 6 mukhi and it worked wonders for me). Wearing three beads of 2 mukhi rudraksh or wearing it as a combination does bring good results!