Sex that leaves your head spinning usually isn’t a cause for alarm. Often, it’s caused by underlying stress or changing positions too quickly.

If sudden dizziness is a sign of something more serious — such as an underlying condition — it’s usually accompanied by other symptoms.

Here’s what to watch for, when to see a doctor, and how to prevent your symptoms from returning.

Benign paroxysmal positional vertigo (BPV) is one of the most common causes of vertigo. Vertigo is a sudden sensation that you or your head are spinning.

It’s triggered by changing the position of your head, such as when you lie down or sit up in bed. You may also experience nausea or vomiting. BPV episodes typically last less than a minute.

Symptoms can come and go, sometimes disappearing for months or years before recurring. The condition isn’t serious and can be treated using special maneuvers of your neck and head.

Your blood pressure can fluctuate throughout the day. It’s influenced by several factors, including your stress levels, body position, time of day, and breathing.

Sometimes, dizziness is a sign of low blood pressure. Infrequent bouts of dizziness usually aren’t cause for concern. You may want to make an appointment with a doctor or other healthcare provider if you’re experiencing other symptoms, such as:

  • blurred vision
  • nausea
  • trouble concentrating
  • fainting

Your doctor can determine what’s causing your blood pressure to drop and advise you on any next steps.

Low blood sugar, or hypoglycemia, occurs when the level of glucose in your blood drops.

Although low blood sugar is more common in people with diabetes, it can happen to anyone. This is known as nondiabetic hypoglycemia.

It’s common to feel lightheaded or dizzy when your blood sugar is low. You may also feel hungry, shaky or jittery, irritable, and have a mild headache.

It can occur after several hours without eating or drinking or after consuming a lot of alcohol. If your symptoms are severe or persist, see a doctor.

Some people may become dizzy during vigorous sexual activity because of an increase in intrathoracic pressure. This is the same type of pressure caused by straining or pushing during a bowel movement.

Research on pressure sensitivity and how it can impact sexual activity is limited, though this may have to do with people being reluctant to report dizziness related to sex.

Certain positions and trying to orgasm may cause you to strain this way. There have been many reported cases of people becoming lightheaded and even fainting while straining during bowel movements.

If you suspect that a pressure sensitivity may be to blame, make an appointment with a doctor or other healthcare provider.

Anxiety — whether ongoing or situational — can cause your heart rate to spike and your breath to become shallow. This can sometimes cause dizziness or hyperventilation.

Anxiety is a common feeling, especially when it comes to sex. You don’t have to have an anxiety disorder diagnosis to experience it.

Many people feel anxious:

  • in a new relationship
  • when having sex for the first time
  • when having relationship problems
  • due to pain or a previous traumatic experience

Other symptoms include:

  • nervousness
  • sweating
  • tense muscles
  • a strong desire to get away from what’s triggering your anxiety

If you think your symptoms are related to anxiety, you may find it helpful to talk to your partner or another trusted person about what you’re feeling.

You may also find it helpful to talk to a doctor or other health professional. They may be able to help you identify the root of your anxiety and help you figure out what to do next.

It’s no secret that sexual arousal can cause your breathing to quicken. If your breathing shortens and quickens rapidly, you’re at risk for hyperventilating. Although sex-related hyperventilation isn’t common, it’s possible.

During hyperventilation, you exhale more than you inhale, which disrupts the balance of carbon dioxide and oxygen. This can cause you to feel dizzy and lightheaded, which can lead to fainting.

In rare cases, sexual activity and orgasm can result in headache and subsequent dizziness.

The exact cause isn’t clear, but researchers suspect they’re triggered by a rapid increase in heart rate and blood pressure. Although pre-orgasm or orgasm headaches can affect anyone, they’re more common in males.

Pre-orgasm headaches are described as a dull pain that comes on during sexual activity and increases with sexual excitement. An orgasm headache causes a sudden explosive headache with intense throbbing that starts just before or at the moment you orgasm.

The pain usually stems from the back of the head and is felt on both sides of the skull. It may last anywhere from one minute to 72 hours.

Several medications used to treat ED list dizziness as a side effect.

This includes:

  • sildenafil (Viagra)
  • tadalafil (Cialis)
  • vardenafil (Levitra)

These medications increase nitric oxide levels in your blood. Although this uptick in nitric oxide can increase blood flow to your penis, it can also result in dizziness.

Other side effects may include:

  • headache
  • muscle ache
  • heartburn
  • diarrhea

If you experience any of these symptoms while taking medication for ED, talk to your healthcare provider. They may be able to prescribe a different medication or recommend a therapy that’s less likely to cause side effects.

If you have a diagnosed heart condition, pay special attention to dizziness or other unusual symptoms. Seek immediate medical attention if you experience dizziness with:

  • shortness of breath
  • swelling in your legs, ankles, or feet
  • vision changes
  • chest pain
  • weakness
  • fatigue

If you’re experiencing symptoms like these but don’t have a diagnosed heart condition, see a doctor as soon as possible.

Dizziness is common in pregnancy — especially in early pregnancy.

Your changing hormone levels cause your blood vessels to dilate, increasing blood flow to the fetus. This decrease in blood pressure can cause you to feel dizzy or lightheaded.

Dizziness may also be tied to low blood sugar. Your blood sugar levels rise and fall as your body adjusts to the pregnancy. Eating small meals throughout the day can help keep your blood sugar balanced.

Other symptoms of early pregnancy include:

  • tender, swollen breasts
  • nausea
  • fatigue
  • headache
  • constipation

The added weight may also cause you to feel dizzy or lightheaded, especially when lying on your back. This is because the growing fetus puts pressure on your vena cava, which is a large vein that supplies blood to your heart from your lower body.

Here are some things you can do to relieve your dizziness and prevent it from happening in the future:

  • Stay hydrated. Drink water before and after sex to avoid dehydration. Dehydration can cause your blood vessels to constrict and cause changes in your blood pressure.
  • Take slow, deep breaths. Hyperventilating causes a rapid decrease in carbon dioxide. This narrows the blood vessels that supply blood to your brain, resulting in light-headedness.
  • Avoid getting up too fast. When you stand, gravity causes blood to pool in your legs and abdomen. This temporarily reduces the amount of blood flowing back to your heart and brain, causing dizziness.
  • Eat regular meals. Eat small meals throughout the day to help keep your blood sugar balanced.

If dizziness after sex is a one-off occurrence — and unaccompanied by other symptoms — it usually isn’t a sign of anything serious. But if it’s happening regularly or otherwise affecting your daily life, make an appointment with a doctor or other healthcare provider.

You should also see a doctor if you experience:

  • blurred vision
  • nausea
  • muscle aches
  • fatigue
  • confusion
  • trouble concentrating
  • fainting

Your doctor can help determine what’s cause your symptoms and develop an appropriate treatment plan.