context: Schizophrenia changes how you think, feel, and act. It might affect you differently from someone else. The symptoms can come and go, too. No one has all of them all of the time. They usually start between ages 16 and 30. Men often get them earlier than women. Oftentimes there is a gradual change in the person before obvious symptoms start. This is sometimes called the prodrome phase. When the disease is in full swing and symptoms are severe, the person with schizophrenia can't tell when certain ideas and perceptions they have are real or not. This happens less often as they get older. People with the condition usually aren't aware that they have it until a doctor or counselor tells them. They won't even realize that something is seriously wrong. If they do happen to notice symptoms, like not being able to think straight, they might chalk it up to things like stress or being tired. If you're concerned that you or someone you know is showing signs of schizophrenia, talk to a doctor or counselor. Positive symptoms are highly exaggerated ideas, perceptions, or actions that show the person can't tell what's real from what isn't. Here the word "positive" means the presence (rather than absence) of symptoms. They can include: Hallucinations. People with schizophrenia might hear, see, smell, or feel things no one else does. The types of hallucinations in schizophrenia include: Auditory. The person most often hears voices in their head. They might be angry or urgent and demand that they do things. It can sound like one voice or many. They might whisper, murmur, or be angry and demanding. Visual. Someone might see lights, objects, people, or patterns. Often it's loved ones or friends who are no longer alive. They may also have trouble with depth perception and distance. Olfactory and gustatory. This can include good and bad smells and tastes. Someone might believe they're being poisoned and refuse to eat. Tactile. This creates a feeling of things moving on your body, like hands or insects. Delusions. These are beliefs that seem strange to most people and are easy to prove wrong. The person affected might think someone is trying to control their brain through TVs or that the FBI is out to get them. They might believe they're someone else, like a famous actor or the president, or that they have superpowers. Types of delusions include: Persecutory delusions. The feeling someone is after you or that you're being stalked, hunted, framed, or tricked. Referential delusions. When a person believes that public forms of communication, like song lyrics or a gesture from a TV host, are a special message just for them. Somatic delusions. These center on the body. The person thinks they have a terrible illness or bizarre health problem like worms under the skin or damage from cosmic rays. Erotomanic delusions. A person might be convinced a celebrity is in love with them or that their partner is cheating. Or they might think people they're not attracted to are pursuing them. Religious delusions. Someone might think they have a special relationship with a deity or that they're possessed by a demon. Grandiose delusions. They consider themselves a major figure on the world stage, like an entertainer or a politician. Confused thoughts and disorganized speech. People with schizophrenia can have a hard time organizing their thoughts. They might not be able to follow along when you talk to them. Instead, it might seem like they're zoning out or distracted. When they talk, their words can come out jumbled and not make sense. Trouble concentrating. For example, someone might lose track of what's going on in a TV show as they're watching. Movement disorders . Some people with schizophrenia can seem jumpy. Sometimes they'll make the same movements over and over again. But sometimes they might be perfectly still for hours at a stretch, which experts call being catatonic. Contrary to popular belief, people with the disease usually aren't violent. Negative symptoms refer to an absence or lack of normal mental function involving thinking, behavior, and perception. You might notice: Lack of pleasure. The person may not seem to enjoy anything anymore. A doctor will call this anhedonia. Trouble with speech. They might not talk much or show any feelings. Doctors call this alogia. Flattening: The person with schizophrenia might seem like they have a terrible case of the blahs. When they talk, their voice can sound flat, like they have no emotions. They may not smile normally or show usual facial emotions in response to conversations or things happening around them. A doctor might call this affective flattening. Withdrawal. This might include no longer making plans with friends or becoming a hermit. Talking to the person can feel like pulling teeth: If you want an answer, you have to really work to pry it out of them. Doctors call this apathy. Struggling with the basics of daily life. They may stop bathing or taking care of themselves. No follow-through. People with schizophrenia have trouble staying on schedule or finishing what they start. Sometimes they can't get started at all. A doctor might call this avolition. Depression has some of the same symptoms, too. They can be hard to spot, especially in teens, because even healthy teens can have big emotional swings between highs and lows. These symptoms reflect how well the person's brain learns, stores, and uses information. Someone with schizophrenia might have a hard time with their working memory. For example, they may not be able to keep track of different kinds of facts at the same time, like a phone number plus instructions. Along with having trouble paying attention, it can be hard for them to organize their thoughts and make decisions.