How do people get love sick?

Love, as a complex emotional experience, cannot cause physical sickness directly. The term "love sick" is often used figuratively to describe the emotional turmoil, heartache, and intense longing associated with unrequited love, a breakup, or the loss of a loved one. While emotional distress can have indirect impacts on a person's physical well-being, such as changes in appetite, sleep patterns, or energy levels, it doesn't cause a specific medical condition.