According to the DSM -5

• Separation anxiety disorder is the fear that someone you love, will leave you, or may be harmed. Even if they don’t, there is a constant fear that they will.
• Selective mutism is the sudden inability to speak in certain social situations, when there is an expectation to speak. But otherwise, they have normal social and language skills.
• Specific phobia are excessive, persistent and irrational fear about specific objects or situations, like an animal or heights or water. The fear and anxiety they feel keeps them away from the said objects or situations, inspite of it not being so dangerous.
• Social anxiety disorder is marked by intense fear when one’s under public attention, for the fear of being humiliated or embarrassed. So, they try to avoid such situations.
• Panic disorder is a sudden attack of fear and anxiety that gradually reaches a peak within minutes, associated with physical symptoms(palpitations, sweating, shortness of breath), cognitive symptoms(fear of dying or going crazy).
• Agoraphobia is the anxiety and fear that is felt when exposed to an open/ enclosed space, crowded unfamiliar locations. The feeling of helplessness, or panic may overwhelm them.
• GAD is the anxiety felt in a more intense fashion than normal about various things. They may also feel restless, easily tired, irritable, poor concentration, muscle tensions and sleep disturbances.
• Substance induced ad are, as the name suggests, caused by substances, withdrawal and certain medications
• Ad due to other mental conditions: anxiety can also be a symptom of another disorder like, hypothyroidism, hypoglycemia, and hypercortisolism, congestive heart failure, arrhythmia, and pulmonary embolism, asthma and pneumonia, B12 or porphyria, neoplasms, encephalitis, and seizure disorder.