The hematocrit and levels tends to decrease with the rise of altitude. Also the level of oxygen decrease as we go up.
Hematocrit is understood as the ratio of red blood to the total period present in the body.
Hemoglobin is defined as a red pigment which is present in red blood cell. This hemoglobin is responsible for carrying oxygen throughout the human body.
Many people feel uneasy when they go off or in higher altitude areas because of decrease in the level of hemoglobin and hematocrit. Most of the people used to carry oxygen cylinder with them.