Like short-term side effects, taking morphine to treat chronic pain can also lead to some long-term side effects that can impact your life. Taking any opioid medication consistently for a long time can cause chronic issues in parts of the body. Gastrointestinal system: Constipation is one of the most widely reported and complained about side effects from taking morphine or related opioid drugs. Between 40 percent and 45 percent of patients on opioid therapy report struggling with constipation. About 25 percent experienced nausea, which affects appetite and can further change the digestive system. A doctor likely will prescribe laxatives, but chronic constipation can damage the bowels, leading to vomiting, bloating, and abdominal bleeding. Orally consumed opioids like morphine may also lead to ulcers. Respiratory system: An acute risk of abusing too much morphine involves suppressed breathing, which can lead to oxygen deprivation and death. Over time, regular doses of morphine can mildly suppress breathing, which also causes oxygen deprivation, but chronic low levels of oxygen are harmful in a different way. They can damage the brain, lungs, and heart, among other organs. About 10 percent of people taking opioids long-term experience hypoxemia, or blood oxygen saturation levels of less than 90 percent. It is also important to note that physical tolerance to analgesic effects and euphoric effects does not necessarily parallel tolerance to respiratory effects. Misusing or abusing morphine can lead to deadly respiratory depression even if you do not feel intoxicated. Cardiovascular system: A study of Medicare patients with arthritis, who were receiving opioids for chronic pain, found that about 77 percent had an increased risk of cardiovascular events like myocardial infarction and heart failure. The risk increased the longer opioid drugs, including morphine, were taken. During the first month of treatment, risks were no different than the control group, while after 180 days of opioid treatment, different opioids increased the risk of heart problems at different rates. Central nervous system (brain and spinal cord): Because morphine and other opioids release endorphins, dopamine, serotonin, and norepinephrine, long-term consumption of these drugs can change structures in the brain that interact with, and rely on, these neurotransmitters. Mood disorders increase. For example, about 38 percent of people who take opioids for a long time have comorbid clinical depression. Ongoing opioid therapy also paradoxically increases the risk of hyperalgesia or increased pain sensations. People who take morphine or related medications for six months or more to treat moderate or severe pain are more likely to feel higher levels of pain if and when they stop taking morphine. Increased pain sensitivity is one of the leading reasons that doctors are prescribing opioids at lower rates in addition to the high risk of addiction. Musculoskeletal system: Dizziness from low blood pressure leads to an increased risk of fainting and falling while taking morphine, which increases the risk of bone fractures from an injury. Taking opioids for a long time is also associated with muscle weakness and less muscle tone, which may be due to lethargy, feeling ill or dizzy consistently, or chronic hypoxia. Endocrine system: Hormone regulation changes the longer opioids like morphine are consumed. Both male and female hormones are affected, leading to a lower sex drive and reduced fertility. Morphine and other opioids also impact the body’s management of all other hormones, including thyroid and metabolism hormones, growth hormones, adrenaline, and pituitary hormones. This can change one’s mood, appetite, and physical growth, among other effects. Immune system: Morphine and fentanyl, in particular, hurt the immune system. They can suppress one’s immune response, leading to an increased risk of illness and infection. The cause is believed to be interaction with the mu-opioid receptors in the brain, which regulate all immune cells. The impact on the pituitary and adrenal glands also changes how the immune system responds to infections.