Costochondritis: This is a common condition characterized by inflammation of the cartilage that connects the ribs to the breastbone, leading to chronic rib pain. It is often related to repetitive strain or minor trauma.

Musculoskeletal Strain: Overuse or direct injury to the muscles between the ribs can cause chronic pain.
Osteoarthritis: Wear and tear on the joints where the ribs meet the spine or breastbone can lead to chronic rib pain.
Fibromyalgia: A condition characterized by widespread musculoskeletal pain, including the rib area.

Pulmonary Embolism: Although less common, a pulmonary embolism can cause sudden onset of chest pain that may be perceived as rib pain, and is life-threatening if not promptly treated.
Myocardial Infarction: Chest pain related to heart attacks can sometimes be felt in the rib area, especially if the pain is referred.
Pneumonia or Pleuritis: Infections or inflammation of the lung or the lining around the lung can cause sharp chest pain that may feel like rib pain.
Osteoporotic Fractures: Especially in older adults or those with osteoporosis, chronic rib pain could be due to stress fractures.

Tietze's Syndrome: A rare condition similar to costochondritis but involves the inflammation of the cartilages and surrounding tissues.
Sickle Cell Disease: Can cause episodes of severe pain, including chest pain, due to vaso-occlusive crises.
Multiple Myeloma: A type of blood cancer that can cause bone pain, including in the ribs, due to bone lesions.
Rib Tumors: Both benign and malignant tumors of the ribs can cause chronic pain.