context: People who are confused and easily forget things don't necessarily have dementia. Many treatable diseases and conditions have symptoms similar to Alzheimer's disease and other forms of dementia. Dementia is any memory loss or thinking problem caused by changes in your brain. Alzheimer's is just one type. Your memory also can be harmed by many other health issues, such as a stroke, Parkinson's disease, or a buildup of fluid on your brain. If you notice symptoms that have you concerned, see a doctor right away. He'll give you a thorough exam that may include taking a sample of your blood for testing, brain imaging, and neurological testing to figure out what's going on with your health and get you help. If you're depressed, you may find it hard to focus or remember things you need to do. You also may sleep too much or too little, not want to spend time with your friends and loved ones, and feel hopeless much of the time. People with Alzheimer's also can experience these things, but a physical exam and a conversation about your symptoms should help your doctor make the right diagnosis. When bacteria enters your urethra (the tube urine flows through when you pee), it sometimes can cause a urinary tract infection ( UTI) that can spread to your bladder or kidneys. In some people, especially those of advanced age, UTIs can cause a sudden onset of symptoms that look like Alzheimer's. You may get confused, upset, sleepy, or have trouble paying attention. Some people hallucinate -- believe they see or hear something no one else can. If your urine is tested and shows that you have an infection, you'll probably be given antibiotics to clear it up. The thyroid is a small butterfly-shaped gland in the front of your neck. It makes hormones that help your organs work and control how well your body uses food for fuel. If your thyroid is working too fast or too slow, it can affect your mental health. People who don't make enough thyroid hormone have what's called hypothyroidism. Parts of your body work too slowly. This can affect your thoughts. You may find it hard to learn new things or recall an event that just took place. If you're making too much thyroid hormone, you have hyperthyroidism. This can also make it hard for you to focus. And you may feel anxious or depressed. In severe cases, you can feel like you're losing touch with the real world. If your doctor finds that your thyroid isn't working as it should, you may need to take medication every day to keep your hormones at normal levels. Some people see their symptoms get better right away. For others, it can take a few months. People with diabetes can have a hard time keeping the right balance of insulin and blood sugar in their bloodstream. If your blood sugar levels drop too low, your body and brain don't have enough fuel to work as they should. This is called hypoglycemia. If it's severe, you can get confused doing even a basic daily task. You also can become clumsy, appear drunk, or maybe even faint. Often, you'll feel better if you eat or drink a small amount of food that's high in sugar. If that doesn't help, you should seek medical attention right away. Some ticks carry harmful bacteria that can get into your system through a bite. This causes an illness called Lyme disease. If the bacteria stays in your blood for a long time, it can affect your nervous system and short-term memory. Some people say they feel like they have "brain fog." You could have trouble keeping up with what others are saying. And daily tasks also may take more effort. Symptoms can show up months or even years after a tick bite. Lyme disease can be treated with antibiotics, but you might still have symptoms. The earlier it's caught, the easier it is to treat. If you're low on B12, you may feel lost or easily "get turned around." Some people also feel tingling in their arms and legs. Your body needs this vitamin to make red blood cells, nerves, and DNA, but it can't make B12 itself. It has to get it from food. Since B12 is only found in animal products, people who follow a vegetarian diet might not get enough. Other people can't absorb enough B12 from food. This could be the case if you have a condition like celiac disease or Crohn's disease, which affects how your body breaks down food. Using heartburn drugs also can cause trouble. Your body needs enough stomach acid to pull B12 from the food you eat. Your doctor can do a blood test to check your B12 levels. If yours is low, a vitamin supplement can help. Many drugs -- like antihistamines, anti-nausea medicine, steroids, and bladder relaxants -- can cause symptoms that look like dementia. This is a greater risk for older people. The older you get, the harder your body has to work to fight the toxic effects of some drugs. Plus, you may need to take more than one drug at a time, and they can interact with each other and cause side effects like confusion. If you think a medicine you take is hurting your memory or slowing your thoughts, talk to your doctor. Dysfunction of the vestibular system - which includes the inner ear and brain - can cause problems with balance and often, cognitive function. Vertigo, Meniere's disease, and labyrinthitis are a few vestibular disorders.