Cracked corners of the mouth.
Moniliasis of the mouth and lips.
Rotting and blistering of the mouth.
If the person is not in the state of Sawm ﴿صَوۡم﴾, it is Sunnah to gargle the throat. One who gargles regularly will not suffer from tonsillitis and he will be saved from several types of throat infections including throat cancer.
The lungs need air, free from germs, smoke and dust, with about 80% humidity. To provide this type of air, Allah عَزَّوَجَلَّ has bestowed the nose upon us. To humidify the air, nose produces about one-fourth gallon of moisture. There are microscopic and invisible bristles in the nose. These bristles kill the germs coming with the air. In addition, these bristles also provide protection and are called Lysozyme. With this, nose protects eyes from infection.
اَلْـحَمْـدُ لـِلّٰـه عَزَّوَجَلَّ! One who performs Wudu rinses his nose with water and thus this important organ (nose) gets cleaned. The electric properties of water improve the ability of bristles and thus a Muslim is saved from several complex diseases of nose by virtue of Wudu. Sniffing water into the nose (as is done during Wudu) is very beneficial for those patients who have chronic flu and wounds in the nose.