<unk> s are a cluster of mental<unk> s characterized by significant and uncontrollable feelings of<unk>  and fear such that a person's social, occupational, and personal function are significantly impaired.<unk>  may cause physical and cognitive symptoms, such as restlessness, irritability, easy fatiguability, difficulty concentrating, increased heart rate, chest pain, abdominal pain, and a variety of other symptoms that may vary based on the individual. In casual discourse, the words<unk>  and fear are often used interchangeably. In clinical usage, they have distinct meanings:<unk>  is defined as an unpleasant emotional state for which the cause is either not readily identified or perceived to be uncontrollable or unavoidable, whereas fear is an emotional and physiological response to a recognized external threat. The umbrella term<unk>  refers to a number of specific<unk> s that include fears (phobias) or<unk>  symptoms. There are several types of<unk> s, including generalized<unk> , specific phobia, social<unk> , separation<unk> , agoraphobia, panic<unk> , and selective mutism. The individual<unk>  can be diagnosed using the specific and unique symptoms, triggering events, and timing. If a person is diagnosed with an<unk> , a medical professional must have evaluated the person to ensure the<unk>  cannot be attributed to another medical illness or mental<unk> . It is possible for an individual to have more than one<unk>  during their life or at the same time and<unk> s are marked by a typical persistent course. For individuals with<unk> , there are numerous treatments and strategies that can improve their mood, behaviors, and ability to function in daily life.
Anxiety disorder
Caffeine
Depression 
Hyperthyroidism
Mood disorder
Cannabis (drug)
Diving disorders
Cardiovascular disease