Final answer:
A broken bone after a fall is often a sign of osteoporosis because weakened bones can fracture more easily than normal, making it the correct answer from the provided options.
Step-by-step explanation:
Osteoporosis is an age-related bone disease characterized by a decrease in bone mass, leading to bones that are more fragile and susceptible to fractures. While osteoporosis can be symptomless, a broken bone after a fall is often a sign of this disease because bones weakened by osteoporosis can fracture more easily. Symptoms like headache, thirst and frequent urination, and shortness of breath are not typical signs of osteoporosis and could indicate other health issues. The most dangerous aspect of osteoporosis involves osteoporotic fractures, which can greatly impact mobility and can lead to serious complications such as deep vein thrombosis, pulmonary embolism, and pneumonia. These risks increase for the elderly, who are already prone to falls due to factors like poor eyesight and balance issues. Therefore, among the options provided, a broken bone after a fall is the correct answer, which corresponds to choice 'A'.