Blood pressure changes can trigger symptoms depending on how the blood flow is affected. High blood pressure is called hypertension and often has no recognizable symptoms, which is why it often is called the "silent killer." Sudden bouts of low blood pressure, called hypotension, typically are accompanied by obvious symptoms.
Dizziness
Doctors at the Mayo Clinic report that many people can live successfully with consistently low blood pressure. The main symptom associated with the condition is dizziness. Lightheadnesses is more common among people with low blood pressure when they stand up too quickly, leave a hot bath or become dehydrated. While the feeling may pass quickly, it should be monitored. Blood pressure levels lower than 90 over 60 can be dangerous. Dizziness can lead to fainting and serious falls. Low blood pressure is usually a sign of an underlying condition such as internal bleeding, a severe infection or an allergic reaction.
Headaches
People with hypertension often experience headaches accompanied by light dizziness. Dull headaches that cannot be treated with painkillers usually are most apparent when blood pressure levels reach dangerous proportions, such as when the top systolic measurement of blood pressure tops 160. Researchers at Merck report that patients with a condition called pheochromocytoma experience rapid spikes in blood pressure that produce a severe headache, nausea, heavy sweating and tremors. Sometimes, the patient becomes pale and anxious.
Increased Heart Rate
The body was built for survival by increasing its heart rate and blood pressure when in danger. Stress can mimic the fight-or-flight responses and increase blood pressure temporarily while the patient is angry, frustrated or pressured. While temporary blood pressure spikes can be controlled with relaxation techniques, they can cause permanent heart damage if left uncontrolled.
Drowsiness
People with a history of high blood pressure or heart disease should be concerned when they become drowsy for no apparent reason. Doctors at the University of Maryland Medical Center report that malignant hypertension or accelerated hypertension is life-threatening and should receive immediate emergency care. In addition to a drowsy feeling, patients should watch for signs of confusion accompanied by nausea. As the blood pressure spikes, the patient may develop a severe headache while becoming drowsy and have trouble focusing his vision. Respiratory problems also can develop when blood pressure rises to dangerous levels.
