Apana Mudra= Keeping index finger and ring finger straight, the tip of the thumb should be touched by ring finger and middle finger.
Useful in diabetes
piles
diseases related to vata
constipation,
urinary obstruction and
kidney diseases,
teeth troubles
It causes perspiration thus foreign matter of the body is thrown out and body gets purified.

Prana Mudra (Mudra of Life):
Bend ring finger and little finger and touch the tip of thumb with their tips keeping the remaining two fingers stretched. As it is the mudra of life, it improves the quality of life by increasing strength. It also removes free radicals from blood.

Duration: No specific duration. One can practice it for any length of time.

Benefits: It improves immunity. Improves the eye sight and helps in other disorders of eyes. It improves the vitamin deficiency and hence fatigue also. — 

Apana Vayu Mudra (Mudra of Heart):
The tips of the middle finger and ring finger touch the tip of thumb, while the index finger touches the base of thumb and little finger stretched out.

It benefits the heart. It works like injection in the reduction of heart attack. It is as powerful as sorbitate tablet. It reduces the gas content in body.

Time duration: Practice it as many times as you can. Heart patients and BP patients can practice it for 15 minutes daily twice for better results.

Benefits:
It strengthens the heart and regularizes palpitation
It regulates excretory system
It redeems gastric trouble
Gyan Mudra Effective in cases of mental ailment, imparts happiness, the intellect develops, memory is sharpened.

Method Join the tips of the index finger and thumb and keep the other 3 fingers stretched and joined.

All students should practice it.
Also, patients of mental disorders
Prithvi Mudra Makes body sturdy. One experiences happiness.

Method Join the tip of the thumb and ring finger.

Must for those, Who wants to increase their wt.
or, having skin problem. 

Surya Mudra
Bend the ring finger and press it with thumb. It stimulates the thyroid gland.

Duration: Practice it daily twice for 5 to 15 minutes.

Benefits: It reduces cholesterol in body and helps in reducing weight, reduces anxiety & corrects indigestion problems.

I practice it daily during vajrasana ,which i do just after lunch/dinner.

Shoonya Mudra Relief in diseases and pains relating to the ear.

Method Press the middle finger on the base of the thumb and keep the thumb on middle finger. Keep the other three fingers straight..

 
Varun Mudra Improves the deteriorated quality of blood due to shortage of water & gives freshness to the body.

Method Join the tip of the thumb and little finger.

For person having Blood disorders & kidney disorders. —

 

Mudras are an effective technique for a wellness lifestyle given the minimal physical effort and time investment. But to feel full benefits Mudras have to be coupled with simple Yogic dietary, meditation so gross blockages of body channels are removed for Mudras to be fully effective.

 

Mudras
The physical body is made up of five elements namely - Air, Water, Fire, Earth and Aakash (ether - the tiny intercellular spaces in the human body).

Imbalance of these elements disrupts the immunity system and causes disease.

Deficiencies in any of these elements can be made up by connecting one part of the body with another in a particular manner through Mudras.

When a finger representing an element is brought into contact with the thumb, that element is brought into balance. Therefore the disease caused by the imbalance is cured. Mudras start electromagnetic currents within the body which balance various constituting elements and restore health. The joining of fingers creates an effect on the human body.

Five Fingers for Five Elements
* Thumb Fire
* Index Air
* Middle Aakash
* Ring Earth
* Little Water

— with Osho Shailendra.

How to start each Mudra session
1. Wash your hands with water.
2. Then rub your hands against each other about 10 times and hold hands before your Navel Chakra (this will help energy to flow in your hands).
3. When fingers touch the pressure exerted should always be very light and the hands should be relaxed.
4. Mudras can be done in any position. One can be seated, standing, lying down and even walking.
5. The body should be loose and relaxed and cantered. It is important not to be tense because that will hinder the flow of energy.
6. After preparing for the practicing session, there are the following ways to practice the same:
7. If you are seated, sit with your back straight, either with legs crossed or on a straight-backed chair.
8. Put your fingers together as described in each Mudra. Just exert that much pressure to feel the flow of energy.
9. Go slow with the Mudras. You should not rush into them but try a few with patience.

— with Anil Babbar.