These health-related causes and impacts of elevated hematocrit levels have been reported: 1  Fall in plasma levels. 2  Sleep apnea. 3  Dehydration. 4  In cases of dengue fever, a high hematocrit is a danger sign of an increased risk of dengue shock syndrome.
The Hmong traditionally farmed in the mountainous areas of China, Vietnam, Laos, and Thailand. Most of the Hmong were subsistence farmers who grew only enough food to feed their families, because farming was difficult in the mountainous regions where most of them lived.
Many Hmong people migrated from Laos to Thailand following the victory of the Pathet Lao in the late 1970s. While some ended up in refugee camps, others settled in mountainous areas becoming one of the ethnic groups in Thailand referred to as hill tribes in that country.