What is considered hypotensive for an adult based on systolic BP?

Hypotension in adults is generally defined as a systolic blood pressure that falls below 90 mmHg. This level indicates that the blood pressure is insufficient for normal blood flow to organs, which can lead to inadequate perfusion and potentially life-threatening situations. A systolic blood pressure of 90 mmHg is considered the threshold where patients may start to exhibit signs and symptoms of reduced circulatory capacity, such as dizziness, fainting, or shock.

While options like 80 mmHg suggest more severe hypotension, it's important to note that 90 mmHg represents the recognized cutoff point in clinical practice for diagnosing hypotension in adults. Thus, any systolic blood pressure below this value is typically classified as hypotensive.