Star Wars has revealed several ways the Jedi can lose the Force, both in canon and Legends. When Luke Skywalker met Yoda for the first in The Empire Strikes Back, the aged Jedi Master gave him a briefing on the Force. "Life creates it, makes it grow," Yoda explained. "Its energy surrounds us and binds us." According to Yoda, the Force is the power of life itself, and it permeates everything that is. Given that is the case, most viewers assume it is impossible for someone to be cut off from the Force.
This is not the case. In fact, the in-universe book Chronicles of the Jedi hints it is not uncommon for a Jedi to be cut off from the Force, or alternatively for this connection to become unstable. According to this book, which purports to be compiled by a Jedi Master, there are multiple avenues to restore this sacred link. "Jedi counselors are specially trained to help others work through traumatic events when individual meditation is not enough," the book notes. If it is actually quite common for Jedi to lose access to the Force, then it is naturally intriguing to look at all the known scenarios where beings have lost (or been stripped of) their Force connection.
6 Some Jedi Can Lose The Force Through Disease 
The only known canon example of a Jedi who lost access to the Force is Sskeer, a Trandoshan Jedi who lived during the High Republic Era. Sskeer lost the Force through disease, suffering from an illness that affects his species called Magrak Syndrome. This causes a Trandoshan to experience rage and aggression, and the mind's attempt to stave off the encephalopathic disease makes it impossible for him to connect to the Force. Sskeer ultimately came to understand even this was according to the will of the Force, however, because the timing – occurring just as a species of Force predators called the Nameless were unleashed on the galaxy – made him the only Jedi who could stand against the growing darkness.
5 Jedi Can Lose Their Force Power Through Injury 
As powerful as he may have been, Darth Vader's potential was actually reduced because of the injuries he sustained on Mustafar. Darth Vader's powers were diminished precisely because he was now a cyborg, more machine than man, with so many of his limbs replaced by artificial ones. As explained in Star Wars: Episode I – The Phantom Menace, Force-sensitives are symbionts with the midi-chlorians living within their cells. When Anakin lost his limbs, he naturally lost the midi-chlorians living in those cells as well.
4 Jedi & Sith Can Be Closed To The Force 
It is possible for a Jedi to cut themselves off from the Force, so they cannot sense anything through it. Luke Skywalker, distraught after Ben Solo's fall to the dark side, retreated to the planet Ahch-To and performed this feat; not only could he no longer be detected in the Force, he also could not sense anything else going on in the galaxy. He had no idea Hosnian Prime had been destroyed, and he did not sense the death of his friend Han Solo. Force ghosts like Master Yoda presumably could not visit Luke until he reconnected to the Force.
In canon, a number of other Jedi have attempted to cut themselves off from the Force, or at least reduce their awareness of it. During the High Republic Era, Jedi Master Elzar Mann – shaken by his vulnerability to the dark side – cut himself off from the Force for a time; according to Mike Chen's novel Brotherhood, Anakin Skywalker did the same at one point when he was just a Padawan. Jedi Knight Cere Junda suppressed her connection to the Force during the Dark Times of the Empire's reign, fearful she would fall to the dark side.
