Differential Diagnosis for 65-year-old Male with Flank Pain

Single most likely diagnosis

• Musculoskeletal strain or injury: The patient's symptoms of sharp, shooting pain in the flank area that worsens with specific movements, such as standing up from a bent position, suggest a musculoskeletal origin. This type of pain is often associated with strain or injury to the muscles or ligaments in the back or flank area.

Other Likely diagnoses

• Kidney stones: Although the patient's pain is intermittent and related to movement, kidney stones can cause severe, sharp pain that may radiate to the flank area. The fact that the pain is on one side increases the likelihood of kidney stones.
• Degenerative disc disease or herniated disc: The patient's age and the nature of the pain, which is exacerbated by certain movements, could suggest a spinal cause such as degenerative disc disease or a herniated disc pressing on nerves that refer pain to the flank area.
• Costochondritis or rib injury: Pain in the flank area can sometimes be referred from the chest wall, particularly if there is inflammation of the cartilage that connects the ribs to the sternum (costochondritis) or if there is a rib injury.

Do Not Miss diagnoses

• Pyelonephritis or kidney infection: Although less likely given the intermittent and movement-related nature of the pain, an infection of the kidney (pyelonephritis) could present with flank pain and is a serious condition that requires prompt treatment.
• Abdominal aortic aneurysm: This is a potentially life-threatening condition that could present with back or flank pain, especially if the aneurysm is expanding or leaking. The patient's age increases the risk for this condition.
• Pulmonary embolism: In some cases, pulmonary embolism can refer pain to the flank area, especially if the embolism is located in the lower parts of the lungs. This is a life-threatening condition that requires immediate diagnosis and treatment.

Rare diagnoses

• Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic pain, among other symptoms like hypertension and palpitations.
• Spinal tumors: Tumors affecting the spine, either primary or metastatic, can cause pain that is exacerbated by movement and can be localized to one side.
• Amyloidosis: A condition characterized by the deposition of abnormal proteins (amyloid) in various tissues, which can cause a wide range of symptoms including pain in the flank area due to kidney involvement.