Hindi popular names of Mercury Line - Budh Rekha, Swasthaya Rekha or Vyapar Rekha.
It starts from the center of the lower portion of palm or near the mount of the Moon and runs upwards towards the mount of Mercury. It could have been included in the major lines except that it is absent in a large number of palms. It is also known by some other names, e.g., line of Health, line of Liver or Hepatica. This line is a very important indicator of the state of health specially related to the digestive system and functioning of the liver, hence the related names. If this line is clearly marked, is straight and faultless, not joined to the life-line, it indicates good health, good memory and good business acumen. In this sense, the line of Mercury has remarkable resemblance to the astrological characteristics attributed to Virgo, the moolatrikona sign of Mercury, the planet. Virgo being the 6th house of Kaalapurusha is also the custodian of health and disease in general. A good line of Mercury brings forth the best Mercurian qualities.
Cheiro disagrees with other authors on palmistry and suggests that this line actually starts from the mount of Mercury and travels down the palm as a man grows older. If and when it touches the life-line, it may cause death, even if the Life-line is long. In such a case, the line of Health should be strongly marked in the hand. If it is weak, it only indicates weak constitution and not death.
It is best to be without this line at all, since, in practical terms, if a line is there, it is bound to have some defect, however small. Complete absence denotes a robust and healthy constitution. It is absolutely imperative to closely examine the line of Mercury for any kind of health problem. When the line is twisted and irregular it indicates biliousness and liver complaints; when formed in small pieces, bad digestion; when made up of small islands with long filbert nails danger to lungs and chest. If the line is the same but the nails are broad, it indicates throat trouble. If this line is heavily marked and exists only between head and heart lines, it indicates brain fever. This line should always be seen along with nails, Life line defects and other health marks in the hand.
Important post on Health Line In Hindi