Dizziness and low blood pressure after hip or knee replacement

If you feel lightheaded, weak, unsteady, nauseated, sweaty, or as though your vision is dimming, stop the transfer or walk. Sit or lie down safely with help. Do not rush to the bathroom, lean on an unsecured walker, or keep walking to “test” whether the feeling will pass.

Postoperative orthostatic intolerance is commonly described as dizziness, lightheadedness, blurred vision, nausea, or faintness when moving upright. A study of primary hip and knee arthroplasty defined an orthostatic event as syncope, lightheadedness, or dizziness that limited walking or required treatment. Review the PubMed study.

Symptoms may begin when moving from lying to sitting, sitting to standing, or during the first few minutes of walking. Patients describe lightheadedness, tunnel or gray vision, ringing in the ears, nausea, sudden warmth, sweating, weakness, unsteadiness, or a feeling that they may faint. Some people have a measured blood-pressure drop; others have similar symptoms without meeting a formal blood-pressure definition.

MedlinePlus explains that orthostatic hypotension is a fall in blood pressure when changing from lying down to standing. Low blood pressure matters most when it causes symptoms such as dizziness, fainting, confusion, or shock. Read the MedlinePlus overview.

Early recovery combines several stresses. Anesthesia and sedating medicines may still affect balance and alertness. Opioids, muscle relaxants, sleep medicines, and some nausea medicines can add drowsiness or lower blood pressure. Blood-pressure medicines and diuretics may need review. Blood loss, fluid shifts, reduced drinking, vomiting, fever, and prolonged time in bed can also contribute.

Orthostatic intolerance has been documented during early mobilization after fast-track hip and knee arthroplasty and can delay rehabilitation or discharge. See the early-mobilization study after hip replacement. The cause is often multifactorial, so a normal incision does not rule out a medication, hydration, anemia, cardiac, or other medical problem.

“Dizziness” can mean lightheadedness, spinning, imbalance, medication sedation, visual disturbance, or generalized weakness. A spinning sensation triggered by head movement may behave differently from faintness on standing. New neurologic symptoms, an irregular heartbeat, low oxygen, infection, blood loss, or a blood clot can also present with weakness or dizziness.

MedlinePlus lists a sudden blood-pressure drop, dehydration, getting up too quickly, and certain medicines among common causes of dizziness, but it also notes many other possible causes. Review the MedlinePlus dizziness overview. Do not self-diagnose repeated episodes solely from a home blood-pressure number.

Use a calm, repeatable response that protects you from a fall:

Move from lying to sitting, pause at the edge of the bed, move the ankles, and make sure vision and balance feel normal before standing. Stand with the prescribed walker and a trained helper when symptoms have occurred. Pause again before walking. A 2025 knee-replacement study found that allowing time between lying, sitting, and standing affected early orthostatic-intolerance symptoms; the authors also noted that standardized prevention guidance remains limited. Review the study.

This is not permission to create your own rehabilitation protocol. The physical therapist and surgical team should individualize the sequence, weight-bearing plan, assistive device, and level of supervision.

Poor intake, vomiting, diarrhea, fever, diuretics, and warm conditions can worsen dehydration. Signs may include thirst, dry mouth, dark urine, reduced urination, rapid heart rate, and blood pressure that falls on standing. See the MedlinePlus dehydration guidance.

Follow the fluid and electrolyte plan given by your team. Patients with heart failure, kidney disease, low sodium, or a prescribed fluid restriction should not simply force large amounts of water. If nausea or poor appetite is limiting intake, review the JRH nausea and hydration guide and contact the team when you cannot keep fluids down.

Make a complete list of prescription medicines, over-the-counter products, supplements, and the exact times taken. Opioids, sedatives, muscle relaxants, some nausea medicines, blood-pressure medicines, and diuretics can contribute to dizziness, sedation, or low pressure. Combining medicines or alcohol can increase risk.

Call the prescribing or surgical team for instructions rather than skipping, doubling, or permanently stopping a medicine on your own. The team may want to review the dose, timing, hydration status, blood pressure trend, kidney function, or other clinical factors before making a change.

Some blood loss is expected with joint replacement, but dizziness with marked fatigue, shortness of breath, rapid heartbeat, pallor, worsening weakness, or inability to progress may prompt evaluation for anemia or bleeding. Bruising around the operated area can be expected, yet rapidly expanding swelling, persistent wound bleeding, black or bloody stool, vomiting blood, or blood in the urine is not something to watch casually.

Anticoagulants and antiplatelet medicines are often prescribed to reduce clot risk. Do not stop them without medical direction. Report bleeding concerns promptly so the team can balance clot prevention and bleeding risk.

Walking and transfers must be safe before discharge. If standing causes faintness, the team may allow more recovery time, give fluids when appropriate, review medicines, check blood pressure or laboratory results, and repeat therapy later. Staying overnight is sometimes safer than forcing a same-day goal.

The JRH same-day discharge guide explains common reasons an intended outpatient knee replacement becomes an overnight stay. A delayed discharge is not a failed operation; it is a safety decision based on the function and medical status observed that day.

A home blood-pressure cuff can be useful when the team provides a method and thresholds, but technique matters. Use the correct cuff size, rest before measuring, keep the arm supported, and record the position, time, symptoms, pulse, recent medicines, and fluid intake. A single number without context can mislead.

Do not stand alone just to obtain an “upright” reading if you are at risk of fainting. If the team wants lying, sitting, and standing measurements, have a capable helper present and follow their timing instructions. Symptoms can deserve review even when a home reading looks normal.

During the first days, a caregiver should know how to guard transfers, where the walker belongs, and whom to call. Keep the phone within reach, use a clear illuminated path, and avoid loose rugs, pets underfoot, and carrying objects while using the walker. The JRH fall-prevention guide covers the broader home setup.

If dizziness has occurred, do not shower alone, climb stairs without the recommended help, or walk outside in heat merely because the previous episode resolved. Ask the team when independent mobility is reasonable.

When contacting the surgical team, be ready to report:

Call promptly for repeated dizziness, a near-fainting episode, new low readings outside the parameters you were given, worsening weakness, inability to walk safely, poor fluid intake, vomiting, reduced urination, fever, medication uncertainty, or concern for anemia or bleeding. Also call after any fall, even if the replaced joint does not immediately hurt.

A sudden change from yesterday’s function matters. The team may recommend medication review, hydration guidance, laboratory testing, an electrocardiogram, evaluation for infection or bleeding, or in-person assessment. Do not wait for the next routine appointment when symptoms are recurring or progression has reversed.

Call 911 for fainting with injury or failure to recover normally, chest pain, sudden shortness of breath, coughing up blood, severe breathing difficulty, signs of stroke, a new severe headache, sustained rapid or irregular heartbeat with weakness, severe confusion, uncontrolled bleeding, or signs of shock such as cold clammy skin and marked weakness.

Do not drive yourself. After joint replacement, dizziness combined with chest symptoms, neurologic symptoms, major bleeding, or collapse requires urgent evaluation rather than a portal message.

Before leaving Oʻahu or returning to a neighbor island, confirm that you can sit, stand, transfer, and walk without recurrent faintness. Carry the medication list and postoperative contact numbers, know the nearest emergency department, and identify who will stay with you during early recovery. Heat and travel can complicate hydration and safe mobility.

If you have repeated symptoms before a flight or long drive, call the surgical team rather than assuming travel will be tolerated. The JRH bed-transfer guide can help with home setup, but dizziness requires its own medical and safety plan.

Many early episodes improve as anesthesia clears, intake normalizes, medicines are adjusted, and mobility increases. Still, faintness is a warning to pause—not a test of determination. Safe recovery means addressing the cause, preventing a fall, and restoring confident movement step by step.

If dizziness or low blood pressure is interfering with recovery after hip or knee replacement, schedule an orthopedic consultation or contact the postoperative team for individualized guidance.