Measurement is not recommended for individuals with severe heart disease or persistent arrhythmia.
Some diseases that affect the autonomic nervous system can impair the reliability of the results and complicate the interpretation.
Acute diseases are not an inhibitory factor with measurement, but can affect results. For example, fever raises body’s state of stress and heart rate, which could show as increased stress state in results.
NOTE! Firstbeat Life is intended to promote well-being, not to diagnose or treat diseases.
Some medications, such as a beta-blocker, affect your heart rate and may therefore impact your results. Asthma and allergy medications, long-acting sleep medications, and strong painkillers can also affect your heart rate and thus results. The more conditions and medications a person have, more difficult it is to make reliable interpretations.
Pregnancy is not an inhibitory factor to measurement, but comparing the results to reference values is not advised. After the first trimester of pregnancy, physiological changes (eg increased heart rate, hormonal changes) may already be significant with the interpretation. Changes during early pregnancy and possible nausea, etc. can also affect the results. Child's heart rate does not affect the mother's heart rate signal, so pregnancy does not interfere the heart rate interval measurement.