If you’re feeling dizzy, you may wonder if your medication is the culprit behind this sometimes frustrating sensation. “I just can’t seem to pinpoint the cause of my dizziness,” said one member of MyBCTeam.

Dizziness is a possible side effect of tamoxifen (Soltamox), which you might take to either treat or reduce your risk of breast cancer. Continue reading to learn more about the possible causes of dizziness and how tamoxifen could be involved.

What Is Dizziness?

“Dizziness” is a broad term that can describe a wide range of symptoms. If you feel dizzy, you might feel:

• Unsteady on your feet
• Faint
• Woozy
• Weak
• Light-headed
• Disoriented or confused

You might also have the sense that the room is spinning.

What Causes Dizziness?

Just as there are many ways to describe dizziness, there are also many causes. For example, you might feel dizzy if something affects your sense of balance. Your brain uses information from your eyes, ears, muscles, skin, and nerves to tell your body how to stay balanced. If any of these parts of the body aren’t working well, you could feel dizzy. Several conditions or medications also can cause dizziness.

Inner Ear Conditions

The vestibular system, an organ in your inner ear, is one of the main ways your body controls balance. Inner ear disorders, such as benign paroxysmal positional vertigo or even an ear infection, can disrupt your sense of balance and make you feel dizzy.

It’s possible to experience dizziness from tamoxifen in addition to other conditions that cause this symptom. A MyBCTeam member starting tamoxifen commented, “I’m a little nervous because I already have dizziness issues from a bad ear.”

Heart Conditions

A heart condition could affect how blood flows to your brain and throughout your body, making you feel dizzy. Examples of heart-related problems that can cause dizziness include:

• Hypotension (low blood pressure)
• Arrhythmia (irregular heartbeat)
• Atherosclerosis (narrowed arteries)

Breast cancer treatments can also cause heart problems, like heart failure. In heart failure, the heart can’t pump blood well enough to meet the body’s oxygen needs, which could lead to dizziness. Breast cancer treatments that can cause heart problems include:

• Doxorubicin (such as Adriamycin)
• Trastuzumab (Herceptin)
• Radiation therapy

Neurologic Conditions

Any condition that affects your brain can also cause dizziness. According to Cleveland Clinic, migraine headaches affect about 12 percent of Americans and are especially common among women. Dizziness is a common migraine symptom.

“I have a history of migraines. After taking tamoxifen, I developed daily dizzy spells and was diagnosed with migraine-associated vertigo (MAV). Basically, my migraines changed into a monster,” one MyBCTeam member shared.

Other Medical Conditions

Additional conditions that often cause dizziness include:

• Anemia
• Dehydration
• Anxiety
• Pain
• Heat exposure
• Postural tachycardia syndrome

Medications

Dizziness can be a side effect of certain medications. These include:

• Blood pressure medications
• Antihistamines (allergy drugs)
• Antidepressants
• Pain medications

Breast cancer treatments that might cause dizziness include:

• Some types of chemotherapy
• Trastuzumab
• Hormonal therapy, including tamoxifen, anastrozole (Arimidex), toremifene (Fareston), fulvestrant (Faslodex), and letrozole (Femara)

Several MyBCTeam members have asked if others experience dizziness while taking breast cancer treatments. One asked, “Does anyone have heart palpitations and dizziness while taking paclitaxel?”

Another member asked, “Anyone else have dizziness while taking letrozole?”

Is Dizziness a Side Effect of Tamoxifen?

Dizziness is listed as an infrequent side effect in clinical trials, affecting about 8 percent of participants taking tamoxifen.

No research addresses how tamoxifen can cause dizziness, but this symptom could be related to other potential side effects. You may experience dizziness alone or along with other side effects of tamoxifen, several of which overlap with potential causes of dizziness.

Menopauselike side effects, such as hot flashes (hot flushes), vaginal dryness, and night sweats, are also common with tamoxifen. These side effects can make you feel overheated and dizzy.

Pain is another possible cause of dizziness. In some people, tamoxifen can cause bone or muscle pain that could lead to dizziness.

Tamoxifen can also increase your risk of developing blurred vision caused by cataracts (cloudy areas in the lens of your eye). Being unable to see as well as you should could make you feel dizzy.

Managing Dizziness

“There is nothing fun about dizziness or falling!” commented a MyBCTeam member.

If you experience dizziness, you can do the following to help prevent complications and falls:

• Find a place to sit or lie down as soon as you start to feel dizzy.
• Don’t stand or sit up too fast.
• Try not to move your head too quickly.
• Keep your living area well lit and clutter free so you don’t trip.
• Wear supportive shoes.
• Use a cane or walker if needed.
• Keep your phone with you so you can call for help if you fall.
• Avoid driving when you feel dizzy.

Avoiding certain substances that can worsen dizziness may help, including:

• Caffeine
• Salt
• Alcohol
• Tobacco

When To Call a Doctor

Dizziness caused by a medication usually goes away on its own. However, if your dizziness doesn’t get better or affects your quality of life, you should contact your cancer care team right away. Your doctor may make changes to your medication or treat other medical conditions that could be worsening your dizziness.

Make sure to be specific when describing this symptom. For example, do you feel like the room is spinning, or do you feel more light-headed? Here’s how one MyBCTeam member described their dizziness: “The room is gently spinning, like when I used to drink too much.”

Dizziness as a Symptom of a Serious Tamoxifen Side Effect

In rare cases, dizziness can indicate a serious side effect of tamoxifen. If you experience certain symptoms along with dizziness, you should seek medical advice and go to the emergency department as soon as possible.

For example, tamoxifen increases your risk of blood clots. You might have a blood clot if you experience dizziness along with any of the following symptoms:

• Chest pain
• Shortness of breath
• Coughing with blood
• Pain or swelling in one or both of legs

Tamoxifen also can increase your risk of stroke. Call your doctor and get emergency care right away if you suddenly experience dizziness plus any of the following symptoms:

• Weakness or numbness in your face, arms, or legs
• Confusion
• Vision problems
• Trouble walking
• Severe headache

Never hesitate to check with your doctor even if you’re not experiencing potentially serious symptoms along with your dizziness. Your health care team can help you figure out what’s making you feel dizzy and how best to avoid or manage this — and any other — symptom.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 64,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you experienced dizziness while taking tamoxifen? What tips do you have for managing this symptom? Share your experiences in the comments below, or start a conversation by posting on your Activities page.