ABLUTION AND HEALTH PURITY
In Islam, ablution, or Wudu', is to wash one’s face, hands, arms, head and feet with water. Wudu or Wazu is the Islamic procedure for washing parts of the body using water often in preparation for formal prayers (Salah).
Wudu literally means cleanliness and in Shari'ah (Islamic Law) it is washing specified parts of the body like hands, face, head and feet with water. Without Wudu, one cannot perform Salah. 
The process of washing the organs usually exposed to dust is no doubt of a great significance to public health. These body parts are exposed all day long to numerous numbers of microbes counted in millions in every cubic centimeters of air. These microbes are in a constant offensive state against the human body at the exposed areas of skin. In ablution, microbes are taken by a surprise sweep from the surface of the skin, specially with perfect massaging and enough pouring of water, as guided by the Prophet (PBUH). Following such a process, no dirt or germs are left on the body except what Allah decrees.
Science has proved the effect of sun rays, particularly the ultra violet ones, in causing skin carcinoma. This effect decreases very well with the consequence of ablution, as it constantly dampens the surface of the skin with water, particularly the parts exposed to such rays. This helps protect the surface and internal layer cells of the skin from the harmful impact of rays. 
According to Dr. MAGOMEDOV, Chinese medicine says that there are more than 700 BASes, and sixty-six of them have quick reflex therapy effects and are named the drastic (or aggression or antique or prime-elements) spots.
Out of these sixty-six spots, sixty-one of them are located in zones required for ablution while the other five are located between the ankle and knee.
Thus, ablution becomes a kind of treatment complex, which includes the hydromassage of the BAS, their thermal and physical stimulation.
Dr. Magomedov said that his studies were triggered by his solemn belief that the five-time-a-day Muslim prayers were bound to have not only an indisputable spiritual effect but were also bound to have a purely physical healing effect as well.
Ablution, helps prevent skin cancer.This is his explanation: the areas that are washed during ablution are the parts of the body that are most prone to be exposed to pollution, whether it is pollution from the internal secretions of the body on to the skin surface, such as sweat, or whether it is external. Ablution, removes this pollution five times a day, and hence maintains a clean outside layer of skin, which in turn helps the cells underneath to function properly.
Also, washing with water helps invigorate the ends of the blood vessels, as well as the nerves and glands that are near the skin surface, and hence helps them perform their functions efficiently. [Salem, Mukhtar, Prayers: A sport for the soul and body, CAIRO, The Arab Modern Center (1990), pg. 52.] 
Allah (Glory be to Him) says in Qur’an: “O you who believe! when you prepare for prayer, wash your faces, and your hands (and arms) to the elbows; Rub your heads (with water); and (wash) your feet to the ankles.” Qur’an .Surah Ma’idah 5:6 
One should perform wudhu before the prayer, for the Prophet Muhammad ﷺ said: "Prayer is not accepted without purification….” Sahih Muslim 224
Abu Hurairah (R) reported that the Messenger of Allahﷺ, said, "When the Muslim - or believing - slave does wudu' and washes his face, every wrong thing at which his eyes have looked leaves with the water - or with the last drop of water. When he washes his hands, every wrong thing which his hands have touched leaves with the water - or with the last drop of water. When he washes his feet every wrong thing to which his feet have walked leaves with the water or with the last drop of water, until he emerges cleansed of sins." Sahih Al Muslim 148 and 475, Muwttah Malik 32.
'Umar ibn al-Khattab (R) reported that the Prophet Muhammadﷺ, said, "No one among you does wudu' and does wudu' thoroughly or adequately - and then testifies, 'There is no god but Allah (Glory be to Him) Alone with no partner and I testify that Muhammad is His slave and Messenger' without the eight doors of the Garden being opened to him so that he can enter by whichever of them he wishes." Tirmidhi Vol 1:55 
The following actions will cause the Wudu to be broken:
If there is no water available to perform wudhu or ghusl, or there is a factor present which prevents the use of water, such as illness, or the inability to use water, it is lawful to perform Tayammum.
Tayammum takes the place of water in purifying oneself from states of impurity, and it is performed as follows: