The continent can be broken into four major landform regions: the Coastal Plains, the Eastern Highlands, the Central Lowlands and the Western Plateau. These landform regions have been created by movements in the Earth's crust, river erosion and changes in climate and sea level.
Causes of Low HGB and Low HCT. Figuring out hematocrit levels in the blood is done through Mean Corpuscular Volume or MCV and Red Cell Distribution Width or RDW. These tests determine whether someone is suffering from low Hgb and/or low HCT levels in their blood and can help doctors determine a cause. 1.Anemia is the direct result of a low red blood cell count.iguring out hematocrit levels in the blood is done through Mean Corpuscular Volume or MCV and Red Cell Distribution Width or RDW. These tests determine whether someone is suffering from low Hgb and/or low HCT levels in their blood and can help doctors determine a cause.
As a result, the gland can't make enough thyroid hormone. Other things that can lead to low levels of thyroid hormone include surgery to remove the thyroid gland and radiation therapy for cancer. Less common causes include viral infections and some drugs, such as amiodarone and lithium.t makes hormones that control the way your body uses energy. Having a low level of thyroid hormone affects your whole body. It can make you feel tired and weak. If hypothyroidism is not treated, it can raise your cholesterol levels.