The diagnosis of<unk> s is made by symptoms, triggers, and a person's personal and family histories. There are no objective biomarkers or laboratory tests that can diagnose<unk> . It is important for a medical professional to evaluate a person for other medical and mental causes for prolonged<unk>  because treatments will vary considerably. Numerous questionnaires have been developed for clinical use and can be used for an objective scoring system. Symptoms may be vary between each subtype of generalized<unk> . Generally, symptoms must be present for at least six months, occur more days than not, and significantly impair a person's ability to function in daily life. Symptoms may include: feeling nervous, anxious, or on edge; worrying excessively; difficulty concentrating; restlessness; irritability. Questionnaires developed for clinical use include the State-Trait<unk>  Inventory (STAI), the Generalized<unk>  7 (GAD-7), the Beck<unk>  Inventory (BAI), the Zung Self-Rating<unk>  Scale, and the Taylor Manifest<unk>  Scale. Other questionnaires combine<unk>  and depression measurement, such as the Hamilton<unk>  Rating Scale, the Hospital<unk>  and Depression Scale (HADS), the Patient Health Questionnaire (PHQ), and the Patient-Reported Outcomes Measurement Information System (PROMIS). Examples of specific<unk>  questionnaires include the Liebowitz Social<unk>  Scale (LSAS), the Social Interaction<unk>  Scale (SIAS), the Social Phobia Inventory (SPIN), the Social Phobia Scale (SPS), and the Social<unk>  Questionnaire (SAQ-A30). Differential diagnosis<unk> s differ from developmentally normal fear or<unk>  by being excessive or persisting beyond developmentally appropriate periods. They differ from transient fear or<unk> , often stress-induced, by being persistent (e.g., typically lasting 6 months or more), although the criterion for duration is intended as a general guide with allowance for some degree of flexibility and is sometimes of shorter duration in children. The diagnosis of an<unk>  requires first ruling out an underlying medical cause. Diseases that may present similar to an<unk> , including certain endocrine diseases (hypo- and hyperthyroidism, hyperprolactinemia), metabolic disorders (diabetes), deficiency states (low levels of vitamin D, B2, B12, folic acid), gastrointestinal diseases (celiac disease, non-celiac gluten sensitivity, inflammatory bowel disease), heart diseases, blood diseases (anemia), and brain degenerative diseases (Parkinson's disease, dementia, multiple sclerosis, Huntington's disease). Several drugs can also cause or worsen<unk> , whether in intoxication, withdrawal, or from chronic use. These include alcohol, tobacco, cannabis, sedatives (including prescription benzodiazepines), opioids (including prescription painkillers and illicit drugs like heroin), stimulants (such as caffeine, cocaine and amphetamines), hallucinogens, and inhalants.
Anxiety disorder
Caffeine
Depression 
Hyperthyroidism
Mood disorder
Cannabis (drug)
Diving disorders
Cardiovascular disease