The most essential difference between the two is that their positioning is completely different - alternative therapy is a set of specific disease intervention/health adjustment methods that are independent of modern mainstream evidence-based medicine, while holistic health is an underlying way of looking at health problems and is not bound to any specific intervention method.
Many people tend to confuse the two, mostly because the promotion of alternative therapies often binds the concept of "holistic conditioning." You may have encountered a similar scene: you go to a street physical therapy shop for shoulder and neck pain, and the boss applies an unknown herbal ointment to you while saying that this is a holistic health therapy, which is much better than the hospital only prescribing painkillers. In fact, the herbal ointments and so-called meridian unblocking techniques he uses for you fall into the category of alternative therapies, and they just use the name of overall health for marketing.
Of course, the two are not completely opposite. The core of overall health is to treat people as a complete system, rather than a collection of separate lesions. Whether it is a mainstream medical plan or a proven alternative therapy, as long as it is beneficial to a person's overall health, it can be included in the plan. For example, I previously followed up on a patient with chronic migraine. The neurologist prescribed him preventive drugs and suggested that he try acupuncture from a regular institution to relieve the pain during the attack. He also adjusted his work and rest, reduced caffeine intake, and did mindfulness meditation three times a week to reduce stress triggers. The whole plan is a typical holistic health approach, in which acupuncture is an alternative therapy that has been supported by certain evidence-based treatments. It is only an optional intervention here, not overall health itself.
Nowadays, there is a lot of controversy about these two concepts. On the one hand, many practitioners of alternative therapies deliberately confuse the concepts, package and sell methods without any scientific verification as "holistic health solutions", and even encourage users to stop regular treatment, which in turn delays the disease.; On the other side, there are also voices that completely reject alternative therapies. They feel that anything with the word "holistic" is pseudoscience. In fact, it is unnecessary. Nowadays, many mainstream medical treatments for chronic diseases have long been based on holistic health ideas. For example, the management of high blood pressure and diabetes has long been more than just prescribing medication. Doctors will give you adjustment suggestions from many aspects such as your diet, exercise, mood, and living environment. These are all aspects of overall health and have nothing to do with alternative therapies.
There used to be an Aunt Zhang in the community who had suffered from high blood pressure for more than ten years. Two years ago, she was deceived by the people at the health center downstairs, saying that eating their wall-breaking herbal powder could replace antihypertensive drugs and that it was "a holistic conditioning from the root." As a result, she became dizzy after taking it for three months, and her blood pressure soared to 172. She was later transferred to our chronic disease management team. We didn't let her take any special health products. We worked with the cardiology doctor to adjust the appropriate dosage for her, and based on her preferences. She was given a low-intensity exercise plan of 20 minutes a day for her habit of square dancing. She was also asked to replace her usual pickled radish with fresh salad dishes in terms of diet. She was also reminded to worry less about her son’s house purchase and not to be angry all the time. After half a year, her blood pressure stabilized between 125 and 135, and even the dizziness she often suffered from before was reduced. The aunt always said later that true holistic conditioning does not mean you buy things randomly, but really incorporates your whole life into the plan.
It doesn’t matter if you really can’t tell the difference between the two. Just remember a simple criterion: Anyone who says that their “holistic health plan” must use a specific product or asks you to stop regular treatment is basically using holistic health as a guise to sell alternative therapies. Real holistic health will never exclude useful methods, let alone bind specific products.

Vali 