Some times, we would have stood up quickly and would have felt dizzy immediately. Then, we would have grabbed the wall and sat down slowly. This is quite common in us and there is no need to worry much.
If the dizziness persists for a longer time, then we must not be very casual regarding that. We must consult a doctor immediately as it could be a serious issue also.
Various reasons why we feel dizzy when we stand up are
Overheating and dehydration:
When the temperature is too hot, we must drink enough water or else it could lead to severe dehydration in us. It is noteworthy that when the environment temperature increases then the BP decreases naturally and we could feel light headedness and dizziness etc. It is necessary to drink enough water in the day to stay hydrated. By this, we could avoid dizziness due to dehydration.
Consumption of alcohol:
We could feel dizzy when we drink alcohol because the intake of alcohol would constrict the blood vessels in us leading to reduced blood flow. This would make the body to work harder to regulate BP. Hence, after drinking alcohol and standing up we would feel dizzy. This dizziness could be avoided by totally quitting alcohol or atleast by reducing the intake etc.
Vigorous exercises:
The muscles in us would encourage blood flow to the heart when we do vigorous exercises. It must be noted that when we rest then the blood would rush to the extremities. The dizziness is caused due to this sudden rush of blood along with the exertion on the lungs. Various examples of vigorous exercises are weight lifting, running, swimming etc. It is important that we must sit for some time after doing these types of exercises to lower the heart rate. By this, we could avoid feeling dizzy when standing up.
Medications:
Point here is that certain medications would alter our BP and due to this we could feel dizzy when we stand up. Examples are diuretics, beta blockers etc that acts specifically on the blood pressure. It is important that we must consult the doctor without fail.
Certain health conditions:
It is true that certain health conditions that are unrelated to BP like GI issues, inner ear issues, hormonal changes could lead to dizziness in us while standing up. There are also other health conditions like heart issues, hypothyroidism, diabetes and neurological issues etc that can create dizziness in us. The dizziness caused due to GI problems could be overcome by reducing stress.
Standing up quickly:
When we stand up, it would take an additionanal effort for the heart to pump blood through the body than while lying down. Not many of us would know that the BP would naturally change depending on the position we are in. This would be to maintain homeostasis. It is worthy to note that when we stand up due to gravity the blood would pool in the lower body and it could take the body few seconds or minute to get adjusted. The BP could fluctuate leading to dizziness.