Low blood pressure in teens can be caused by a number of issues, including pregnancy, heart exhaustion, liver disease, heart failure, certain medications, hormonal complications, bleeding and dehydration. An individual is said to have low blood pressure if they have a reading of 90 mm Hg systolic or 60 mm Hg diastolic, notes Mayo Clinic.
When individuals are injured or experience surgical complications, they may end up losing a lot of blood. This will cause a malfunction in body organs, including the heart, which is why hypotension is experienced. People who are dealing with issues such as diarrhea, vomiting and excessive exercise may also end up being dehydrated, which in essence causes a reduction in blood levels.
Eating a diet that is not balanced can result in a deficiency in vitamin B-12. This means the body will not be able to produce enough red blood cells, thus leading to low blood pressure. The heart is responsible for pumping blood to other parts of the body. However, when affected by conditions such as heart attack or valve complications, it may not be able to pump blood effectively, causing hypotension.
An individual with low blood pressure may experience symptoms including dizziness, lightheadedness and fainting, according to MedicineNet.com. These symptoms usually develop because the brain is not receiving enough oxygen.