Can you name the simple breathing exercise which has the following benefits?

1.Helps to improve memory.
2.Useful in acidity.
3.Helps to cure BP.
4.Cures disorders of kidneys.
5.If practised at bedtime helps to keep away nightmares and get a peaceful sleep.
6.Improves digestion.
7.Beneficial in migraine and headaches.
8.Helps to clear the respiratory system thus increasing immunity to allergies, cough, cold and other respiratory ailments.
9.Reduces wrinkles.
10.Reduces premature greying  and falling of hair.
11.Retards the process of ageying.
12.Gives natural glow to the face.

Yes! it is the "Udgeeth Pranayam".
This pranayam is very easy, anybody can learn and practice.
Method: Sit in any position with back straight. Inhale deeply and exhale slowly with the sound of O.........m. The exhalation takes 15 seconds(10 seconds for long OOOOOOOO and 5 seconds for small mmmm). This is one round. Practice 3 to 10 times daily and see the amazing results!
p.s. For the first time this technique can be learnt under the supervision of a yoga teacher/guru.

Yoga can help you in the following ways:

Stay fit and healthy always. Daily practice asanas and pranayam that suit your time and energy. Ex. Few rounds of Suryanamaskar will keep you fully charged till the next day.

Prevent diseases. Practice important asanas, pranayam or kriyas daily. Ex. Doing jal-neti or Udgeeth pranayam will keep cough, cold, acidity at bay, clearing the respiratory pathway and bringing immunity in the changing seasons.

As a therapy. For instance, if you feel a problem in your ear, start practising "Karna shakti vikasak"(development of hearing power) or if you have started putting on flab on your waist, go for "Kati chakrasana or trikonasana.