What is the best wearable for anxiety and heart rate alerts?

Best overall: Apple Watch for iPhone users, because it has the strongest everyday heart-rate alert ecosystem and solid anxiety-support tools through breathing/mindfulness, sleep, activity, and third-party apps. If you use Android, the best alternative is Samsung Galaxy Watch. If your priority is stress/anxiety insights rather than smartwatch features, consider Fitbit Sense 2 or Garmin Venu 3.

Important caveat: wearables can alert you to high/low or irregular heart-rate patterns, but they do not diagnose anxiety, panic attacks, arrhythmias, or heart disease. If you have fainting, chest pain, shortness of breath, or repeated unexplained alerts, treat that as medical and contact a clinician urgently.